[ { "id": "PY100-E01", "difficulty": "easy", "slug": "reverse_words", "function_name": "reverse_words", "signature": "reverse_words(text: str) -> str", "description": "Return words in reverse order, separated by one space. Words are maximal non-whitespace spans.", "notes": "", "tags": [ "strings" ], "examples": [ { "case_id": "PY100-E01-T01", "input": [ "hello world" ], "expected": "world hello" }, { "case_id": "PY100-E01-T02", "input": [ " one two three " ], "expected": "three two one" } ], "tests": [ { "case_id": "PY100-E01-T01", "input": [ "hello world" ], "expected": "world hello" }, { "case_id": "PY100-E01-T02", "input": [ " one two three " ], "expected": "three two one" }, { "case_id": "PY100-E01-T03", "input": [ "" ], "expected": "" }, { "case_id": "PY100-E01-T04", "input": [ "single" ], "expected": "single" }, { "case_id": "PY100-E01-T05", "input": [ "a\tb\nc" ], "expected": "c b a" }, { "case_id": "PY100-E01-T06", "input": [ "x x" ], "expected": "x x" } ] }, { "id": "PY100-E02", "difficulty": "easy", "slug": "is_palindrome_alnum", "function_name": "is_palindrome_alnum", "signature": "is_palindrome_alnum(text: str) -> bool", "description": "Ignore non-alphanumeric characters and letter case; determine whether the remaining characters form a palindrome.", "notes": "", "tags": [ "strings" ], "examples": [ { "case_id": "PY100-E02-T01", "input": [ "A man, a plan, a canal: Panama" ], "expected": true }, { "case_id": "PY100-E02-T02", "input": [ "race a car" ], "expected": false } ], "tests": [ { "case_id": "PY100-E02-T01", "input": [ "A man, a plan, a canal: Panama" ], "expected": true }, { "case_id": "PY100-E02-T02", "input": [ "race a car" ], "expected": false }, { "case_id": "PY100-E02-T03", "input": [ "" ], "expected": true }, { "case_id": "PY100-E02-T04", "input": [ ".,!" ], "expected": true }, { "case_id": "PY100-E02-T05", "input": [ "0P" ], "expected": false }, { "case_id": "PY100-E02-T06", "input": [ "No lemon, no melon" ], "expected": true } ] }, { "id": "PY100-E03", "difficulty": "easy", "slug": "rotate_right", "function_name": "rotate_right", "signature": "rotate_right(nums: list[int], k: int) -> list[int]", "description": "Return a new list obtained by rotating nums right by k positions; k is nonnegative. Empty input stays empty.", "notes": "", "tags": [ "arrays" ], "examples": [ { "case_id": "PY100-E03-T01", "input": [ [ 1, 2, 3, 4, 5 ], 2 ], "expected": [ 4, 5, 1, 2, 3 ] }, { "case_id": "PY100-E03-T02", "input": [ [ 1, 2 ], 5 ], "expected": [ 2, 1 ] } ], "tests": [ { "case_id": "PY100-E03-T01", "input": [ [ 1, 2, 3, 4, 5 ], 2 ], "expected": [ 4, 5, 1, 2, 3 ] }, { "case_id": "PY100-E03-T02", "input": [ [ 1, 2 ], 5 ], "expected": [ 2, 1 ] }, { "case_id": "PY100-E03-T03", "input": [ [], 7 ], "expected": [] }, { "case_id": "PY100-E03-T04", "input": [ [ 4 ], 100 ], "expected": [ 4 ] }, { "case_id": "PY100-E03-T05", "input": [ [ 1, 1, 2 ], 0 ], "expected": [ 1, 1, 2 ] }, { "case_id": "PY100-E03-T06", "input": [ [ 1, 2, 3 ], 3 ], "expected": [ 1, 2, 3 ] } ] }, { "id": "PY100-E04", "difficulty": "easy", "slug": "unique_in_order", "function_name": "unique_in_order", "signature": "unique_in_order(nums: list[int]) -> list[int]", "description": "Remove duplicate integers, preserving the first occurrence order.", "notes": "", "tags": [ "arrays" ], "examples": [ { "case_id": "PY100-E04-T01", "input": [ [ 1, 2, 1, 3, 2 ] ], "expected": [ 1, 2, 3 ] }, { "case_id": "PY100-E04-T02", "input": [ [] ], "expected": [] } ], "tests": [ { "case_id": "PY100-E04-T01", "input": [ [ 1, 2, 1, 3, 2 ] ], "expected": [ 1, 2, 3 ] }, { "case_id": "PY100-E04-T02", "input": [ [] ], "expected": [] }, { "case_id": "PY100-E04-T03", "input": [ [ 4, 4, 4 ] ], "expected": [ 4 ] }, { "case_id": "PY100-E04-T04", "input": [ [ 3, 2, 1 ] ], "expected": [ 3, 2, 1 ] }, { "case_id": "PY100-E04-T05", "input": [ [ 0, -1, 0, -1 ] ], "expected": [ 0, -1 ] }, { "case_id": "PY100-E04-T06", "input": [ [ 1, 2, 3, 1, 4 ] ], "expected": [ 1, 2, 3, 4 ] } ] }, { "id": "PY100-E05", "difficulty": "easy", "slug": "word_counts", "function_name": "word_counts", "signature": "word_counts(text: str) -> dict[str,int]", "description": "Count lowercase words; a word is a contiguous run of ASCII letters A-Z/a-z. Ignore punctuation, digits and case.", "notes": "", "tags": [ "strings", "hashmap" ], "examples": [ { "case_id": "PY100-E05-T01", "input": [ "Hello, hello! World 123" ], "expected": { "hello": 2, "world": 1 } }, { "case_id": "PY100-E05-T02", "input": [ "" ], "expected": {} } ], "tests": [ { "case_id": "PY100-E05-T01", "input": [ "Hello, hello! World 123" ], "expected": { "hello": 2, "world": 1 } }, { "case_id": "PY100-E05-T02", "input": [ "" ], "expected": {} }, { "case_id": "PY100-E05-T03", "input": [ "One1Two" ], "expected": { "one": 1, "two": 1 } }, { "case_id": "PY100-E05-T04", "input": [ "A a a B" ], "expected": { "a": 3, "b": 1 } }, { "case_id": "PY100-E05-T05", "input": [ "hello_world" ], "expected": { "hello": 1, "world": 1 } }, { "case_id": "PY100-E05-T06", "input": [ "X-Y x" ], "expected": { "x": 2, "y": 1 } } ] }, { "id": "PY100-E06", "difficulty": "easy", "slug": "second_largest_distinct", "function_name": "second_largest_distinct", "signature": "second_largest_distinct(nums: list[int]) -> int | None", "description": "Return the second-largest distinct integer, or null if fewer than two distinct values exist.", "notes": "", "tags": [ "arrays" ], "examples": [ { "case_id": "PY100-E06-T01", "input": [ [ 4, 1, 4, 2 ] ], "expected": 2 }, { "case_id": "PY100-E06-T02", "input": [ [ 1, 1, 1 ] ], "expected": null } ], "tests": [ { "case_id": "PY100-E06-T01", "input": [ [ 4, 1, 4, 2 ] ], "expected": 2 }, { "case_id": "PY100-E06-T02", "input": [ [ 1, 1, 1 ] ], "expected": null }, { "case_id": "PY100-E06-T03", "input": [ [] ], "expected": null }, { "case_id": "PY100-E06-T04", "input": [ [ -5, -2, -3 ] ], "expected": -3 }, { "case_id": "PY100-E06-T05", "input": [ [ 1, 2 ] ], "expected": 1 }, { "case_id": "PY100-E06-T06", "input": [ [ 9, 8, 7, 9 ] ], "expected": 8 } ] }, { "id": "PY100-E07", "difficulty": "easy", "slug": "max_consecutive_ones", "function_name": "max_consecutive_ones", "signature": "max_consecutive_ones(bits: list[int]) -> int", "description": "Return the length of the longest consecutive run of 1s. The list contains only 0s and 1s.", "notes": "", "tags": [ "arrays" ], "examples": [ { "case_id": "PY100-E07-T01", "input": [ [ 1, 1, 0, 1, 1, 1 ] ], "expected": 3 }, { "case_id": "PY100-E07-T02", "input": [ [] ], "expected": 0 } ], "tests": [ { "case_id": "PY100-E07-T01", "input": [ [ 1, 1, 0, 1, 1, 1 ] ], "expected": 3 }, { "case_id": "PY100-E07-T02", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-E07-T03", "input": [ [ 0, 0 ] ], "expected": 0 }, { "case_id": "PY100-E07-T04", "input": [ [ 1, 1, 1 ] ], "expected": 3 }, { "case_id": "PY100-E07-T05", "input": [ [ 1, 0, 1 ] ], "expected": 1 }, { "case_id": "PY100-E07-T06", "input": [ [ 0, 1, 1, 0, 1 ] ], "expected": 2 } ] }, { "id": "PY100-E08", "difficulty": "easy", "slug": "balanced_brackets", "function_name": "balanced_brackets", "signature": "balanced_brackets(text: str) -> bool", "description": "Check proper nesting of (), [], {}. Ignore all other characters.", "notes": "", "tags": [ "stack" ], "examples": [ { "case_id": "PY100-E08-T01", "input": [ "([]){}" ], "expected": true }, { "case_id": "PY100-E08-T02", "input": [ "([)]" ], "expected": false } ], "tests": [ { "case_id": "PY100-E08-T01", "input": [ "([]){}" ], "expected": true }, { "case_id": "PY100-E08-T02", "input": [ "([)]" ], "expected": false }, { "case_id": "PY100-E08-T03", "input": [ "" ], "expected": true }, { "case_id": "PY100-E08-T04", "input": [ "a(b[c]{d})" ], "expected": true }, { "case_id": "PY100-E08-T05", "input": [ "(((" ], "expected": false }, { "case_id": "PY100-E08-T06", "input": [ "}" ], "expected": false }, { "case_id": "PY100-E08-T07", "input": [ "[]{}()" ], "expected": true } ] }, { "id": "PY100-E09", "difficulty": "easy", "slug": "merge_sorted_lists", "function_name": "merge_sorted_lists", "signature": "merge_sorted_lists(a: list[int], b: list[int]) -> list[int]", "description": "Merge two nondecreasing integer lists into one nondecreasing list, retaining duplicates.", "notes": "", "tags": [ "sorting" ], "examples": [ { "case_id": "PY100-E09-T01", "input": [ [ 1, 3, 5 ], [ 2, 4, 6 ] ], "expected": [ 1, 2, 3, 4, 5, 6 ] }, { "case_id": "PY100-E09-T02", "input": [ [], [ 1 ] ], "expected": [ 1 ] } ], "tests": [ { "case_id": "PY100-E09-T01", "input": [ [ 1, 3, 5 ], [ 2, 4, 6 ] ], "expected": [ 1, 2, 3, 4, 5, 6 ] }, { "case_id": "PY100-E09-T02", "input": [ [], [ 1 ] ], "expected": [ 1 ] }, { "case_id": "PY100-E09-T03", "input": [ [ 1, 1 ], [ 1, 2 ] ], "expected": [ 1, 1, 1, 2 ] }, { "case_id": "PY100-E09-T04", "input": [ [], [] ], "expected": [] }, { "case_id": "PY100-E09-T05", "input": [ [ -3, 0 ], [ 0, 5 ] ], "expected": [ -3, 0, 0, 5 ] }, { "case_id": "PY100-E09-T06", "input": [ [ 9 ], [ 1, 2 ] ], "expected": [ 1, 2, 9 ] } ] }, { "id": "PY100-E10", "difficulty": "easy", "slug": "sorted_intersection", "function_name": "sorted_intersection", "signature": "sorted_intersection(a: list[int], b: list[int]) -> list[int]", "description": "Return distinct integers present in both inputs, sorted ascending.", "notes": "", "tags": [ "sets" ], "examples": [ { "case_id": "PY100-E10-T01", "input": [ [ 1, 2, 2, 3 ], [ 2, 2, 4 ] ], "expected": [ 2 ] }, { "case_id": "PY100-E10-T02", "input": [ [], [ 1 ] ], "expected": [] } ], "tests": [ { "case_id": "PY100-E10-T01", "input": [ [ 1, 2, 2, 3 ], [ 2, 2, 4 ] ], "expected": [ 2 ] }, { "case_id": "PY100-E10-T02", "input": [ [], [ 1 ] ], "expected": [] }, { "case_id": "PY100-E10-T03", "input": [ [ 3, 1 ], [ 2, 4 ] ], "expected": [] }, { "case_id": "PY100-E10-T04", "input": [ [ -1, 0 ], [ -1, 1 ] ], "expected": [ -1 ] }, { "case_id": "PY100-E10-T05", "input": [ [ 1, 2 ], [ 1, 2 ] ], "expected": [ 1, 2 ] }, { "case_id": "PY100-E10-T06", "input": [ [ 5 ], [ 5, 5 ] ], "expected": [ 5 ] } ] }, { "id": "PY100-E11", "difficulty": "easy", "slug": "rle_encode", "function_name": "rle_encode", "signature": "rle_encode(text: str) -> list[list]", "description": "Run-length encode adjacent equal characters as [character,count] pairs in original order.", "notes": "", "tags": [ "strings" ], "examples": [ { "case_id": "PY100-E11-T01", "input": [ "aaabbc" ], "expected": [ [ "a", 3 ], [ "b", 2 ], [ "c", 1 ] ] }, { "case_id": "PY100-E11-T02", "input": [ "" ], "expected": [] } ], "tests": [ { "case_id": "PY100-E11-T01", "input": [ "aaabbc" ], "expected": [ [ "a", 3 ], [ "b", 2 ], [ "c", 1 ] ] }, { "case_id": "PY100-E11-T02", "input": [ "" ], "expected": [] }, { "case_id": "PY100-E11-T03", "input": [ "a" ], "expected": [ [ "a", 1 ] ] }, { "case_id": "PY100-E11-T04", "input": [ "aAa" ], "expected": [ [ "a", 1 ], [ "A", 1 ], [ "a", 1 ] ] }, { "case_id": "PY100-E11-T05", "input": [ "11122" ], "expected": [ [ "1", 3 ], [ "2", 2 ] ] }, { "case_id": "PY100-E11-T06", "input": [ "ababa" ], "expected": [ [ "a", 1 ], [ "b", 1 ], [ "a", 1 ], [ "b", 1 ], [ "a", 1 ] ] } ] }, { "id": "PY100-E12", "difficulty": "easy", "slug": "caesar_lower", "function_name": "caesar_lower", "signature": "caesar_lower(text: str, shift: int) -> str", "description": "Shift lowercase ASCII letters by shift modulo 26, preserving all other characters. shift can be negative.", "notes": "", "tags": [ "strings" ], "examples": [ { "case_id": "PY100-E12-T01", "input": [ "abc xyz", 2 ], "expected": "cde zab" }, { "case_id": "PY100-E12-T02", "input": [ "Zoo!", 1 ], "expected": "Zpp!" } ], "tests": [ { "case_id": "PY100-E12-T01", "input": [ "abc xyz", 2 ], "expected": "cde zab" }, { "case_id": "PY100-E12-T02", "input": [ "Zoo!", 1 ], "expected": "Zpp!" }, { "case_id": "PY100-E12-T03", "input": [ "a", -1 ], "expected": "z" }, { "case_id": "PY100-E12-T04", "input": [ "", 99 ], "expected": "" }, { "case_id": "PY100-E12-T05", "input": [ "hello", 26 ], "expected": "hello" }, { "case_id": "PY100-E12-T06", "input": [ "xyz", 5 ], "expected": "cde" } ] }, { "id": "PY100-E13", "difficulty": "easy", "slug": "digital_root", "function_name": "digital_root", "signature": "digital_root(n: int) -> int", "description": "Return the repeated digit sum of nonnegative n until one digit remains.", "notes": "", "tags": [ "math" ], "examples": [ { "case_id": "PY100-E13-T01", "input": [ 0 ], "expected": 0 }, { "case_id": "PY100-E13-T02", "input": [ 9 ], "expected": 9 } ], "tests": [ { "case_id": "PY100-E13-T01", "input": [ 0 ], "expected": 0 }, { "case_id": "PY100-E13-T02", "input": [ 9 ], "expected": 9 }, { "case_id": "PY100-E13-T03", "input": [ 38 ], "expected": 2 }, { "case_id": "PY100-E13-T04", "input": [ 9999 ], "expected": 9 }, { "case_id": "PY100-E13-T05", "input": [ 10 ], "expected": 1 }, { "case_id": "PY100-E13-T06", "input": [ 123456789 ], "expected": 9 } ] }, { "id": "PY100-E14", "difficulty": "easy", "slug": "count_vowels", "function_name": "count_vowels", "signature": "count_vowels(text: str) -> int", "description": "Count occurrences of ASCII vowels a,e,i,o,u, case-insensitively.", "notes": "", "tags": [ "strings" ], "examples": [ { "case_id": "PY100-E14-T01", "input": [ "Hello World" ], "expected": 3 }, { "case_id": "PY100-E14-T02", "input": [ "AEIOU" ], "expected": 5 } ], "tests": [ { "case_id": "PY100-E14-T01", "input": [ "Hello World" ], "expected": 3 }, { "case_id": "PY100-E14-T02", "input": [ "AEIOU" ], "expected": 5 }, { "case_id": "PY100-E14-T03", "input": [ "rhythm" ], "expected": 0 }, { "case_id": "PY100-E14-T04", "input": [ "" ], "expected": 0 }, { "case_id": "PY100-E14-T05", "input": [ "aA!1" ], "expected": 2 }, { "case_id": "PY100-E14-T06", "input": [ "queue" ], "expected": 4 } ] }, { "id": "PY100-E15", "difficulty": "easy", "slug": "longest_common_prefix", "function_name": "longest_common_prefix", "signature": "longest_common_prefix(words: list[str]) -> str", "description": "Return the longest prefix shared by every string; return empty string for empty input.", "notes": "", "tags": [ "strings" ], "examples": [ { "case_id": "PY100-E15-T01", "input": [ [ "flower", "flow", "flight" ] ], "expected": "fl" }, { "case_id": "PY100-E15-T02", "input": [ [ "dog", "racecar", "car" ] ], "expected": "" } ], "tests": [ { "case_id": "PY100-E15-T01", "input": [ [ "flower", "flow", "flight" ] ], "expected": "fl" }, { "case_id": "PY100-E15-T02", "input": [ [ "dog", "racecar", "car" ] ], "expected": "" }, { "case_id": "PY100-E15-T03", "input": [ [] ], "expected": "" }, { "case_id": "PY100-E15-T04", "input": [ [ "alone" ] ], "expected": "alone" }, { "case_id": "PY100-E15-T05", "input": [ [ "a", "a", "a" ] ], "expected": "a" }, { "case_id": "PY100-E15-T06", "input": [ [ "", "abc" ] ], "expected": "" } ] }, { "id": "PY100-E16", "difficulty": "easy", "slug": "is_anagram", "function_name": "is_anagram", "signature": "is_anagram(a: str, b: str) -> bool", "description": "Return true iff strings have identical character multisets. Case and whitespace matter.", "notes": "", "tags": [ "strings" ], "examples": [ { "case_id": "PY100-E16-T01", "input": [ "listen", "silent" ], "expected": true }, { "case_id": "PY100-E16-T02", "input": [ "rat", "car" ], "expected": false } ], "tests": [ { "case_id": "PY100-E16-T01", "input": [ "listen", "silent" ], "expected": true }, { "case_id": "PY100-E16-T02", "input": [ "rat", "car" ], "expected": false }, { "case_id": "PY100-E16-T03", "input": [ "", "" ], "expected": true }, { "case_id": "PY100-E16-T04", "input": [ "aab", "aba" ], "expected": true }, { "case_id": "PY100-E16-T05", "input": [ "A", "a" ], "expected": false }, { "case_id": "PY100-E16-T06", "input": [ "a b", "ab " ], "expected": true } ] }, { "id": "PY100-E17", "difficulty": "easy", "slug": "fizzbuzz_slice", "function_name": "fizzbuzz_slice", "signature": "fizzbuzz_slice(start: int, end: int) -> list[str]", "description": "For each integer n in inclusive [start,end], output FizzBuzz if divisible by 15, Fizz if divisible by 3, Buzz if divisible by 5, otherwise decimal n. If start>end return [].", "notes": "", "tags": [ "math" ], "examples": [ { "case_id": "PY100-E17-T01", "input": [ 1, 5 ], "expected": [ "1", "2", "Fizz", "4", "Buzz" ] }, { "case_id": "PY100-E17-T02", "input": [ 14, 16 ], "expected": [ "14", "FizzBuzz", "16" ] } ], "tests": [ { "case_id": "PY100-E17-T01", "input": [ 1, 5 ], "expected": [ "1", "2", "Fizz", "4", "Buzz" ] }, { "case_id": "PY100-E17-T02", "input": [ 14, 16 ], "expected": [ "14", "FizzBuzz", "16" ] }, { "case_id": "PY100-E17-T03", "input": [ 0, 0 ], "expected": [ "FizzBuzz" ] }, { "case_id": "PY100-E17-T04", "input": [ 5, 3 ], "expected": [] }, { "case_id": "PY100-E17-T05", "input": [ -3, 3 ], "expected": [ "Fizz", "-2", "-1", "FizzBuzz", "1", "2", "Fizz" ] }, { "case_id": "PY100-E17-T06", "input": [ 30, 31 ], "expected": [ "FizzBuzz", "31" ] } ] }, { "id": "PY100-E18", "difficulty": "easy", "slug": "matrix_diagonal_sum", "function_name": "matrix_diagonal_sum", "signature": "matrix_diagonal_sum(matrix: list[list[int]]) -> int", "description": "For a square matrix, return the sum of both diagonals; count their shared center once.", "notes": "", "tags": [ "matrix" ], "examples": [ { "case_id": "PY100-E18-T01", "input": [ [ [ 1, 2 ], [ 3, 4 ] ] ], "expected": 10 }, { "case_id": "PY100-E18-T02", "input": [ [ [ 5 ] ] ], "expected": 5 } ], "tests": [ { "case_id": "PY100-E18-T01", "input": [ [ [ 1, 2 ], [ 3, 4 ] ] ], "expected": 10 }, { "case_id": "PY100-E18-T02", "input": [ [ [ 5 ] ] ], "expected": 5 }, { "case_id": "PY100-E18-T03", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-E18-T04", "input": [ [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] ], "expected": 25 }, { "case_id": "PY100-E18-T05", "input": [ [ [ 0, 0 ], [ 0, 0 ] ] ], "expected": 0 }, { "case_id": "PY100-E18-T06", "input": [ [ [ -1, 2 ], [ 3, -4 ] ] ], "expected": 0 } ] }, { "id": "PY100-E19", "difficulty": "easy", "slug": "transpose_matrix", "function_name": "transpose_matrix", "signature": "transpose_matrix(matrix: list[list[int]]) -> list[list[int]]", "description": "Transpose a rectangular matrix. Empty matrix returns []; nonempty rows have equal length.", "notes": "", "tags": [ "matrix" ], "examples": [ { "case_id": "PY100-E19-T01", "input": [ [ [ 1, 2, 3 ], [ 4, 5, 6 ] ] ], "expected": [ [ 1, 4 ], [ 2, 5 ], [ 3, 6 ] ] }, { "case_id": "PY100-E19-T02", "input": [ [] ], "expected": [] } ], "tests": [ { "case_id": "PY100-E19-T01", "input": [ [ [ 1, 2, 3 ], [ 4, 5, 6 ] ] ], "expected": [ [ 1, 4 ], [ 2, 5 ], [ 3, 6 ] ] }, { "case_id": "PY100-E19-T02", "input": [ [] ], "expected": [] }, { "case_id": "PY100-E19-T03", "input": [ [ [ 1 ] ] ], "expected": [ [ 1 ] ] }, { "case_id": "PY100-E19-T04", "input": [ [ [ 1 ], [ 2 ], [ 3 ] ] ], "expected": [ [ 1, 2, 3 ] ] }, { "case_id": "PY100-E19-T05", "input": [ [ [], [] ] ], "expected": [] }, { "case_id": "PY100-E19-T06", "input": [ [ [ 1, 2 ], [ 3, 4 ] ] ], "expected": [ [ 1, 3 ], [ 2, 4 ] ] } ] }, { "id": "PY100-E20", "difficulty": "easy", "slug": "flatten_once", "function_name": "flatten_once", "signature": "flatten_once(groups: list[list[int]]) -> list[int]", "description": "Flatten exactly one level of nested integer lists, preserving order.", "notes": "", "tags": [ "arrays" ], "examples": [ { "case_id": "PY100-E20-T01", "input": [ [ [ 1, 2 ], [], [ 3 ] ] ], "expected": [ 1, 2, 3 ] }, { "case_id": "PY100-E20-T02", "input": [ [] ], "expected": [] } ], "tests": [ { "case_id": "PY100-E20-T01", "input": [ [ [ 1, 2 ], [], [ 3 ] ] ], "expected": [ 1, 2, 3 ] }, { "case_id": "PY100-E20-T02", "input": [ [] ], "expected": [] }, { "case_id": "PY100-E20-T03", "input": [ [ [], [] ] ], "expected": [] }, { "case_id": "PY100-E20-T04", "input": [ [ [ 1 ], [ 2 ], [ 3 ] ] ], "expected": [ 1, 2, 3 ] }, { "case_id": "PY100-E20-T05", "input": [ [ [ -1, 0 ], [ 0 ] ] ], "expected": [ -1, 0, 0 ] }, { "case_id": "PY100-E20-T06", "input": [ [ [ 1, 1 ], [ 1 ] ] ], "expected": [ 1, 1, 1 ] } ] }, { "id": "PY100-E21", "difficulty": "easy", "slug": "cancel_adjacent_pairs", "function_name": "cancel_adjacent_pairs", "signature": "cancel_adjacent_pairs(text: str) -> str", "description": "Repeatedly remove adjacent equal characters until no such pair remains; case-sensitive.", "notes": "", "tags": [ "stack" ], "examples": [ { "case_id": "PY100-E21-T01", "input": [ "abbaca" ], "expected": "ca" }, { "case_id": "PY100-E21-T02", "input": [ "azxxzy" ], "expected": "ay" } ], "tests": [ { "case_id": "PY100-E21-T01", "input": [ "abbaca" ], "expected": "ca" }, { "case_id": "PY100-E21-T02", "input": [ "azxxzy" ], "expected": "ay" }, { "case_id": "PY100-E21-T03", "input": [ "" ], "expected": "" }, { "case_id": "PY100-E21-T04", "input": [ "aaaa" ], "expected": "" }, { "case_id": "PY100-E21-T05", "input": [ "abBA" ], "expected": "abBA" }, { "case_id": "PY100-E21-T06", "input": [ "aabccb" ], "expected": "" } ] }, { "id": "PY100-E22", "difficulty": "easy", "slug": "majority_element", "function_name": "majority_element", "signature": "majority_element(nums: list[int]) -> int | None", "description": "Return the value appearing strictly more than n/2 times, or null if none exists.", "notes": "", "tags": [ "hashmap" ], "examples": [ { "case_id": "PY100-E22-T01", "input": [ [ 2, 2, 1, 2 ] ], "expected": 2 }, { "case_id": "PY100-E22-T02", "input": [ [ 1, 2, 3 ] ], "expected": null } ], "tests": [ { "case_id": "PY100-E22-T01", "input": [ [ 2, 2, 1, 2 ] ], "expected": 2 }, { "case_id": "PY100-E22-T02", "input": [ [ 1, 2, 3 ] ], "expected": null }, { "case_id": "PY100-E22-T03", "input": [ [] ], "expected": null }, { "case_id": "PY100-E22-T04", "input": [ [ 1 ] ], "expected": 1 }, { "case_id": "PY100-E22-T05", "input": [ [ -1, -1, 2, 2 ] ], "expected": null }, { "case_id": "PY100-E22-T06", "input": [ [ -2, -2, -2, 1, 1 ] ], "expected": -2 } ] }, { "id": "PY100-E23", "difficulty": "easy", "slug": "missing_zero_to_n", "function_name": "missing_zero_to_n", "signature": "missing_zero_to_n(nums: list[int]) -> int", "description": "The length-n array contains each value from 0 through n except one, without duplicates. Return the missing value.", "notes": "", "tags": [ "math", "arrays" ], "examples": [ { "case_id": "PY100-E23-T01", "input": [ [ 3, 0, 1 ] ], "expected": 2 }, { "case_id": "PY100-E23-T02", "input": [ [ 0, 1 ] ], "expected": 2 } ], "tests": [ { "case_id": "PY100-E23-T01", "input": [ [ 3, 0, 1 ] ], "expected": 2 }, { "case_id": "PY100-E23-T02", "input": [ [ 0, 1 ] ], "expected": 2 }, { "case_id": "PY100-E23-T03", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-E23-T04", "input": [ [ 1 ] ], "expected": 0 }, { "case_id": "PY100-E23-T05", "input": [ [ 4, 2, 1, 0 ] ], "expected": 3 }, { "case_id": "PY100-E23-T06", "input": [ [ 5, 4, 3, 2, 1 ] ], "expected": 0 } ] }, { "id": "PY100-E24", "difficulty": "easy", "slug": "two_sum_earliest", "function_name": "two_sum_earliest", "signature": "two_sum_earliest(nums: list[int], target: int) -> list[int]", "description": "Return lexicographically smallest pair of indices [i,j] with i int", "description": "Return the first index of target in sorted nondecreasing nums; -1 when absent.", "notes": "", "tags": [ "binary-search" ], "examples": [ { "case_id": "PY100-E25-T01", "input": [ [ 1, 2, 2, 3 ], 2 ], "expected": 1 }, { "case_id": "PY100-E25-T02", "input": [ [], 1 ], "expected": -1 } ], "tests": [ { "case_id": "PY100-E25-T01", "input": [ [ 1, 2, 2, 3 ], 2 ], "expected": 1 }, { "case_id": "PY100-E25-T02", "input": [ [], 1 ], "expected": -1 }, { "case_id": "PY100-E25-T03", "input": [ [ 1, 2, 3 ], 4 ], "expected": -1 }, { "case_id": "PY100-E25-T04", "input": [ [ 4, 4, 4 ], 4 ], "expected": 0 }, { "case_id": "PY100-E25-T05", "input": [ [ -5, -1, 0 ], -1 ], "expected": 1 }, { "case_id": "PY100-E25-T06", "input": [ [ 1 ], 1 ], "expected": 0 } ] }, { "id": "PY100-E26", "difficulty": "easy", "slug": "ascii_title_words", "function_name": "ascii_title_words", "signature": "ascii_title_words(text: str) -> str", "description": "Convert words separated by ASCII spaces to title case: first character uppercase, remaining lowercase; preserve the exact number of spaces. Inputs contain ASCII letters and spaces only.", "notes": "", "tags": [ "strings" ], "examples": [ { "case_id": "PY100-E26-T01", "input": [ "hello WORLD" ], "expected": "Hello World" }, { "case_id": "PY100-E26-T02", "input": [ " a b " ], "expected": " A B " } ], "tests": [ { "case_id": "PY100-E26-T01", "input": [ "hello WORLD" ], "expected": "Hello World" }, { "case_id": "PY100-E26-T02", "input": [ " a b " ], "expected": " A B " }, { "case_id": "PY100-E26-T03", "input": [ "" ], "expected": "" }, { "case_id": "PY100-E26-T04", "input": [ "PYTHON" ], "expected": "Python" }, { "case_id": "PY100-E26-T05", "input": [ "x" ], "expected": "X" }, { "case_id": "PY100-E26-T06", "input": [ "aBc DEF ghi" ], "expected": "Abc Def Ghi" } ] }, { "id": "PY100-E27", "difficulty": "easy", "slug": "inclusive_prefix_sums", "function_name": "inclusive_prefix_sums", "signature": "inclusive_prefix_sums(nums: list[int]) -> list[int]", "description": "Return cumulative prefix sums, including each current element.", "notes": "", "tags": [ "arrays" ], "examples": [ { "case_id": "PY100-E27-T01", "input": [ [ 1, 2, 3 ] ], "expected": [ 1, 3, 6 ] }, { "case_id": "PY100-E27-T02", "input": [ [] ], "expected": [] } ], "tests": [ { "case_id": "PY100-E27-T01", "input": [ [ 1, 2, 3 ] ], "expected": [ 1, 3, 6 ] }, { "case_id": "PY100-E27-T02", "input": [ [] ], "expected": [] }, { "case_id": "PY100-E27-T03", "input": [ [ -1, 4, -2 ] ], "expected": [ -1, 3, 1 ] }, { "case_id": "PY100-E27-T04", "input": [ [ 0, 0 ] ], "expected": [ 0, 0 ] }, { "case_id": "PY100-E27-T05", "input": [ [ 10 ] ], "expected": [ 10 ] }, { "case_id": "PY100-E27-T06", "input": [ [ 2, -2, 2, -2 ] ], "expected": [ 2, 0, 2, 0 ] } ] }, { "id": "PY100-E28", "difficulty": "easy", "slug": "count_unique_pairs", "function_name": "count_unique_pairs", "signature": "count_unique_pairs(nums: list[int], target: int) -> int", "description": "Count distinct unordered value pairs (a,b) with a<=b, sum target, and enough occurrences when a==b.", "notes": "", "tags": [ "hashmap" ], "examples": [ { "case_id": "PY100-E28-T01", "input": [ [ 1, 2, 3, 2, 4 ], 5 ], "expected": 2 }, { "case_id": "PY100-E28-T02", "input": [ [ 1, 1 ], 2 ], "expected": 1 } ], "tests": [ { "case_id": "PY100-E28-T01", "input": [ [ 1, 2, 3, 2, 4 ], 5 ], "expected": 2 }, { "case_id": "PY100-E28-T02", "input": [ [ 1, 1 ], 2 ], "expected": 1 }, { "case_id": "PY100-E28-T03", "input": [ [ 1 ], 2 ], "expected": 0 }, { "case_id": "PY100-E28-T04", "input": [ [], 0 ], "expected": 0 }, { "case_id": "PY100-E28-T05", "input": [ [ -2, -1, 0, 1, 2 ], 0 ], "expected": 2 }, { "case_id": "PY100-E28-T06", "input": [ [ 0, 0, 0 ], 0 ], "expected": 1 } ] }, { "id": "PY100-E29", "difficulty": "easy", "slug": "group_by_parity", "function_name": "group_by_parity", "signature": "group_by_parity(nums: list[int]) -> list[list[int]]", "description": "Return [even_numbers, odd_numbers], preserving input order within both lists; negative odd numbers are odd.", "notes": "", "tags": [ "arrays" ], "examples": [ { "case_id": "PY100-E29-T01", "input": [ [ 1, 2, 3, 4 ] ], "expected": [ [ 2, 4 ], [ 1, 3 ] ] }, { "case_id": "PY100-E29-T02", "input": [ [] ], "expected": [ [], [] ] } ], "tests": [ { "case_id": "PY100-E29-T01", "input": [ [ 1, 2, 3, 4 ] ], "expected": [ [ 2, 4 ], [ 1, 3 ] ] }, { "case_id": "PY100-E29-T02", "input": [ [] ], "expected": [ [], [] ] }, { "case_id": "PY100-E29-T03", "input": [ [ -3, -2, -1, 0 ] ], "expected": [ [ -2, 0 ], [ -3, -1 ] ] }, { "case_id": "PY100-E29-T04", "input": [ [ 2, 4, 6 ] ], "expected": [ [ 2, 4, 6 ], [] ] }, { "case_id": "PY100-E29-T05", "input": [ [ 1, 3 ] ], "expected": [ [], [ 1, 3 ] ] }, { "case_id": "PY100-E29-T06", "input": [ [ 0 ] ], "expected": [ [ 0 ], [] ] } ] }, { "id": "PY100-E30", "difficulty": "easy", "slug": "rect_overlap_area", "function_name": "rect_overlap_area", "signature": "rect_overlap_area(a: list[int], b: list[int]) -> int", "description": "Axis-aligned rectangles [x1,y1,x2,y2] with x1 int", "description": "All nums positive; return minimum length of a contiguous subarray with sum >= target, or 0 if impossible.", "notes": "", "tags": [ "sliding-window" ], "examples": [ { "case_id": "PY100-M01-T01", "input": [ [ 2, 3, 1, 2, 4, 3 ], 7 ], "expected": 2 }, { "case_id": "PY100-M01-T02", "input": [ [ 1, 1, 1 ], 4 ], "expected": 0 } ], "tests": [ { "case_id": "PY100-M01-T01", "input": [ [ 2, 3, 1, 2, 4, 3 ], 7 ], "expected": 2 }, { "case_id": "PY100-M01-T02", "input": [ [ 1, 1, 1 ], 4 ], "expected": 0 }, { "case_id": "PY100-M01-T03", "input": [ [], 1 ], "expected": 0 }, { "case_id": "PY100-M01-T04", "input": [ [ 5 ], 5 ], "expected": 1 }, { "case_id": "PY100-M01-T05", "input": [ [ 5 ], 6 ], "expected": 0 }, { "case_id": "PY100-M01-T06", "input": [ [ 1, 2, 3, 4 ], 6 ], "expected": 2 } ] }, { "id": "PY100-M02", "difficulty": "medium", "slug": "longest_unique_substring", "function_name": "longest_unique_substring", "signature": "longest_unique_substring(text: str) -> int", "description": "Length of longest substring with no repeated characters; case-sensitive.", "notes": "", "tags": [ "sliding-window" ], "examples": [ { "case_id": "PY100-M02-T01", "input": [ "abcabcbb" ], "expected": 3 }, { "case_id": "PY100-M02-T02", "input": [ "bbbbb" ], "expected": 1 } ], "tests": [ { "case_id": "PY100-M02-T01", "input": [ "abcabcbb" ], "expected": 3 }, { "case_id": "PY100-M02-T02", "input": [ "bbbbb" ], "expected": 1 }, { "case_id": "PY100-M02-T03", "input": [ "pwwkew" ], "expected": 3 }, { "case_id": "PY100-M02-T04", "input": [ "" ], "expected": 0 }, { "case_id": "PY100-M02-T05", "input": [ "abba" ], "expected": 2 }, { "case_id": "PY100-M02-T06", "input": [ "aA" ], "expected": 2 } ] }, { "id": "PY100-M03", "difficulty": "medium", "slug": "longest_k_distinct", "function_name": "longest_k_distinct", "signature": "longest_k_distinct(nums: list[int], k: int) -> int", "description": "Return longest contiguous segment containing at most k distinct integers; k>=0.", "notes": "", "tags": [ "sliding-window" ], "examples": [ { "case_id": "PY100-M03-T01", "input": [ [ 1, 2, 1, 2, 3 ], 2 ], "expected": 4 }, { "case_id": "PY100-M03-T02", "input": [ [ 1, 1, 1 ], 1 ], "expected": 3 } ], "tests": [ { "case_id": "PY100-M03-T01", "input": [ [ 1, 2, 1, 2, 3 ], 2 ], "expected": 4 }, { "case_id": "PY100-M03-T02", "input": [ [ 1, 1, 1 ], 1 ], "expected": 3 }, { "case_id": "PY100-M03-T03", "input": [ [ 1, 2 ], 0 ], "expected": 0 }, { "case_id": "PY100-M03-T04", "input": [ [], 3 ], "expected": 0 }, { "case_id": "PY100-M03-T05", "input": [ [ 1, 2, 3 ], 3 ], "expected": 3 }, { "case_id": "PY100-M03-T06", "input": [ [ 1, 2, 2, 3, 3, 3 ], 2 ], "expected": 5 } ] }, { "id": "PY100-M04", "difficulty": "medium", "slug": "subarray_sum_count", "function_name": "subarray_sum_count", "signature": "subarray_sum_count(nums: list[int], k: int) -> int", "description": "Count nonempty contiguous subarrays whose sum is k. Values may be negative.", "notes": "", "tags": [ "prefix-sum" ], "examples": [ { "case_id": "PY100-M04-T01", "input": [ [ 1, 1, 1 ], 2 ], "expected": 2 }, { "case_id": "PY100-M04-T02", "input": [ [ 1, -1, 0 ], 0 ], "expected": 3 } ], "tests": [ { "case_id": "PY100-M04-T01", "input": [ [ 1, 1, 1 ], 2 ], "expected": 2 }, { "case_id": "PY100-M04-T02", "input": [ [ 1, -1, 0 ], 0 ], "expected": 3 }, { "case_id": "PY100-M04-T03", "input": [ [], 0 ], "expected": 0 }, { "case_id": "PY100-M04-T04", "input": [ [ 0, 0, 0 ], 0 ], "expected": 6 }, { "case_id": "PY100-M04-T05", "input": [ [ 1, 2, 3 ], 3 ], "expected": 2 }, { "case_id": "PY100-M04-T06", "input": [ [ -1, -1, 1 ], -1 ], "expected": 3 } ] }, { "id": "PY100-M05", "difficulty": "medium", "slug": "product_except_self", "function_name": "product_except_self", "signature": "product_except_self(nums: list[int]) -> list[int]", "description": "Return products of all elements except at each index; no division required; empty input yields [].", "notes": "", "tags": [ "arrays" ], "examples": [ { "case_id": "PY100-M05-T01", "input": [ [ 1, 2, 3, 4 ] ], "expected": [ 24, 12, 8, 6 ] }, { "case_id": "PY100-M05-T02", "input": [ [ 0, 1, 2, 3 ] ], "expected": [ 6, 0, 0, 0 ] } ], "tests": [ { "case_id": "PY100-M05-T01", "input": [ [ 1, 2, 3, 4 ] ], "expected": [ 24, 12, 8, 6 ] }, { "case_id": "PY100-M05-T02", "input": [ [ 0, 1, 2, 3 ] ], "expected": [ 6, 0, 0, 0 ] }, { "case_id": "PY100-M05-T03", "input": [ [ 0, 0, 1 ] ], "expected": [ 0, 0, 0 ] }, { "case_id": "PY100-M05-T04", "input": [ [] ], "expected": [] }, { "case_id": "PY100-M05-T05", "input": [ [ -1, 2, -3 ] ], "expected": [ -6, 3, -2 ] }, { "case_id": "PY100-M05-T06", "input": [ [ 5 ] ], "expected": [ 1 ] } ] }, { "id": "PY100-M06", "difficulty": "medium", "slug": "max_circular_subarray", "function_name": "max_circular_subarray", "signature": "max_circular_subarray(nums: list[int]) -> int", "description": "For nonempty nums, return maximum sum of a nonempty contiguous circular subarray; no element may be used twice.", "notes": "", "tags": [ "arrays", "dp" ], "examples": [ { "case_id": "PY100-M06-T01", "input": [ [ 1, -2, 3, -2 ] ], "expected": 3 }, { "case_id": "PY100-M06-T02", "input": [ [ 5, -3, 5 ] ], "expected": 10 } ], "tests": [ { "case_id": "PY100-M06-T01", "input": [ [ 1, -2, 3, -2 ] ], "expected": 3 }, { "case_id": "PY100-M06-T02", "input": [ [ 5, -3, 5 ] ], "expected": 10 }, { "case_id": "PY100-M06-T03", "input": [ [ -3, -2, -3 ] ], "expected": -2 }, { "case_id": "PY100-M06-T04", "input": [ [ 3 ] ], "expected": 3 }, { "case_id": "PY100-M06-T05", "input": [ [ -1, 4, -2, 5 ] ], "expected": 8 }, { "case_id": "PY100-M06-T06", "input": [ [ -5, 5 ] ], "expected": 5 } ] }, { "id": "PY100-M07", "difficulty": "medium", "slug": "spiral_matrix", "function_name": "spiral_matrix", "signature": "spiral_matrix(matrix: list[list[int]]) -> list[int]", "description": "Return rectangular matrix entries in clockwise spiral order starting top-left.", "notes": "", "tags": [ "matrix" ], "examples": [ { "case_id": "PY100-M07-T01", "input": [ [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] ], "expected": [ 1, 2, 3, 6, 9, 8, 7, 4, 5 ] }, { "case_id": "PY100-M07-T02", "input": [ [ [ 1, 2, 3 ] ] ], "expected": [ 1, 2, 3 ] } ], "tests": [ { "case_id": "PY100-M07-T01", "input": [ [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] ], "expected": [ 1, 2, 3, 6, 9, 8, 7, 4, 5 ] }, { "case_id": "PY100-M07-T02", "input": [ [ [ 1, 2, 3 ] ] ], "expected": [ 1, 2, 3 ] }, { "case_id": "PY100-M07-T03", "input": [ [ [ 1 ], [ 2 ] ] ], "expected": [ 1, 2 ] }, { "case_id": "PY100-M07-T04", "input": [ [] ], "expected": [] }, { "case_id": "PY100-M07-T05", "input": [ [ [ 1, 2 ], [ 3, 4 ] ] ], "expected": [ 1, 2, 4, 3 ] }, { "case_id": "PY100-M07-T06", "input": [ [ [ 1 ] ] ], "expected": [ 1 ] } ] }, { "id": "PY100-M08", "difficulty": "medium", "slug": "search_rotated_unique", "function_name": "search_rotated_unique", "signature": "search_rotated_unique(nums: list[int], target: int) -> int", "description": "nums is a rotated strictly increasing array with unique values. Return target index or -1.", "notes": "", "tags": [ "binary-search" ], "examples": [ { "case_id": "PY100-M08-T01", "input": [ [ 4, 5, 6, 7, 0, 1, 2 ], 0 ], "expected": 4 }, { "case_id": "PY100-M08-T02", "input": [ [ 4, 5, 6, 7, 0, 1, 2 ], 3 ], "expected": -1 } ], "tests": [ { "case_id": "PY100-M08-T01", "input": [ [ 4, 5, 6, 7, 0, 1, 2 ], 0 ], "expected": 4 }, { "case_id": "PY100-M08-T02", "input": [ [ 4, 5, 6, 7, 0, 1, 2 ], 3 ], "expected": -1 }, { "case_id": "PY100-M08-T03", "input": [ [], 5 ], "expected": -1 }, { "case_id": "PY100-M08-T04", "input": [ [ 1 ], 1 ], "expected": 0 }, { "case_id": "PY100-M08-T05", "input": [ [ 3, 1 ], 1 ], "expected": 1 }, { "case_id": "PY100-M08-T06", "input": [ [ 1, 2, 3 ], 2 ], "expected": 1 } ] }, { "id": "PY100-M09", "difficulty": "medium", "slug": "find_first_last", "function_name": "find_first_last", "signature": "find_first_last(nums: list[int], target: int) -> list[int]", "description": "Return [first_index,last_index] of target in sorted array; [-1,-1] if absent.", "notes": "", "tags": [ "binary-search" ], "examples": [ { "case_id": "PY100-M09-T01", "input": [ [ 5, 7, 7, 8, 8, 10 ], 8 ], "expected": [ 3, 4 ] }, { "case_id": "PY100-M09-T02", "input": [ [ 5, 7, 7, 8 ], 6 ], "expected": [ -1, -1 ] } ], "tests": [ { "case_id": "PY100-M09-T01", "input": [ [ 5, 7, 7, 8, 8, 10 ], 8 ], "expected": [ 3, 4 ] }, { "case_id": "PY100-M09-T02", "input": [ [ 5, 7, 7, 8 ], 6 ], "expected": [ -1, -1 ] }, { "case_id": "PY100-M09-T03", "input": [ [], 0 ], "expected": [ -1, -1 ] }, { "case_id": "PY100-M09-T04", "input": [ [ 2, 2, 2 ], 2 ], "expected": [ 0, 2 ] }, { "case_id": "PY100-M09-T05", "input": [ [ 1, 2, 3 ], 1 ], "expected": [ 0, 0 ] }, { "case_id": "PY100-M09-T06", "input": [ [ 1, 2, 2, 3 ], 3 ], "expected": [ 3, 3 ] } ] }, { "id": "PY100-M10", "difficulty": "medium", "slug": "merge_intervals", "function_name": "merge_intervals", "signature": "merge_intervals(intervals: list[list[int]]) -> list[list[int]]", "description": "Merge closed intervals [start,end] when overlapping or touching; return sorted merged intervals.", "notes": "", "tags": [ "intervals" ], "examples": [ { "case_id": "PY100-M10-T01", "input": [ [ [ 1, 3 ], [ 2, 6 ], [ 8, 10 ], [ 15, 18 ] ] ], "expected": [ [ 1, 6 ], [ 8, 10 ], [ 15, 18 ] ] }, { "case_id": "PY100-M10-T02", "input": [ [ [ 1, 4 ], [ 4, 5 ] ] ], "expected": [ [ 1, 5 ] ] } ], "tests": [ { "case_id": "PY100-M10-T01", "input": [ [ [ 1, 3 ], [ 2, 6 ], [ 8, 10 ], [ 15, 18 ] ] ], "expected": [ [ 1, 6 ], [ 8, 10 ], [ 15, 18 ] ] }, { "case_id": "PY100-M10-T02", "input": [ [ [ 1, 4 ], [ 4, 5 ] ] ], "expected": [ [ 1, 5 ] ] }, { "case_id": "PY100-M10-T03", "input": [ [] ], "expected": [] }, { "case_id": "PY100-M10-T04", "input": [ [ [ 5, 7 ], [ 1, 2 ] ] ], "expected": [ [ 1, 2 ], [ 5, 7 ] ] }, { "case_id": "PY100-M10-T05", "input": [ [ [ -5, -1 ], [ -2, 2 ] ] ], "expected": [ [ -5, 2 ] ] }, { "case_id": "PY100-M10-T06", "input": [ [ [ 1, 10 ], [ 2, 3 ], [ 4, 8 ] ] ], "expected": [ [ 1, 10 ] ] } ] }, { "id": "PY100-M11", "difficulty": "medium", "slug": "insert_interval", "function_name": "insert_interval", "signature": "insert_interval(intervals: list[list[int]], new_interval: list[int]) -> list[list[int]]", "description": "Insert a closed interval into nonoverlapping sorted closed intervals, merging overlap/touch.", "notes": "", "tags": [ "intervals" ], "examples": [ { "case_id": "PY100-M11-T01", "input": [ [ [ 1, 3 ], [ 6, 9 ] ], [ 2, 5 ] ], "expected": [ [ 1, 5 ], [ 6, 9 ] ] }, { "case_id": "PY100-M11-T02", "input": [ [ [ 1, 2 ], [ 3, 5 ], [ 6, 7 ], [ 8, 10 ], [ 12, 16 ] ], [ 4, 8 ] ], "expected": [ [ 1, 2 ], [ 3, 10 ], [ 12, 16 ] ] } ], "tests": [ { "case_id": "PY100-M11-T01", "input": [ [ [ 1, 3 ], [ 6, 9 ] ], [ 2, 5 ] ], "expected": [ [ 1, 5 ], [ 6, 9 ] ] }, { "case_id": "PY100-M11-T02", "input": [ [ [ 1, 2 ], [ 3, 5 ], [ 6, 7 ], [ 8, 10 ], [ 12, 16 ] ], [ 4, 8 ] ], "expected": [ [ 1, 2 ], [ 3, 10 ], [ 12, 16 ] ] }, { "case_id": "PY100-M11-T03", "input": [ [], [ 1, 2 ] ], "expected": [ [ 1, 2 ] ] }, { "case_id": "PY100-M11-T04", "input": [ [ [ 1, 5 ] ], [ 6, 8 ] ], "expected": [ [ 1, 5 ], [ 6, 8 ] ] }, { "case_id": "PY100-M11-T05", "input": [ [ [ 1, 5 ] ], [ 2, 3 ] ], "expected": [ [ 1, 5 ] ] }, { "case_id": "PY100-M11-T06", "input": [ [ [ -5, -1 ], [ 2, 4 ] ], [ 0, 1 ] ], "expected": [ [ -5, -1 ], [ 0, 1 ], [ 2, 4 ] ] } ] }, { "id": "PY100-M12", "difficulty": "medium", "slug": "minimum_meeting_rooms", "function_name": "minimum_meeting_rooms", "signature": "minimum_meeting_rooms(intervals: list[list[int]]) -> int", "description": "Intervals are [start,end) with start bool", "description": "Pairs [course,prerequisite] impose prerequisite ordering. Return whether all courses can be finished.", "notes": "", "tags": [ "graphs" ], "examples": [ { "case_id": "PY100-M13-T01", "input": [ 2, [ [ 1, 0 ] ] ], "expected": true }, { "case_id": "PY100-M13-T02", "input": [ 2, [ [ 1, 0 ], [ 0, 1 ] ] ], "expected": false } ], "tests": [ { "case_id": "PY100-M13-T01", "input": [ 2, [ [ 1, 0 ] ] ], "expected": true }, { "case_id": "PY100-M13-T02", "input": [ 2, [ [ 1, 0 ], [ 0, 1 ] ] ], "expected": false }, { "case_id": "PY100-M13-T03", "input": [ 0, [] ], "expected": true }, { "case_id": "PY100-M13-T04", "input": [ 3, [ [ 1, 0 ], [ 2, 1 ] ] ], "expected": true }, { "case_id": "PY100-M13-T05", "input": [ 3, [ [ 0, 0 ] ] ], "expected": false }, { "case_id": "PY100-M13-T06", "input": [ 4, [ [ 1, 0 ], [ 3, 2 ] ] ], "expected": true } ] }, { "id": "PY100-M14", "difficulty": "medium", "slug": "lexicographic_toposort", "function_name": "lexicographic_toposort", "signature": "lexicographic_toposort(n: int, edges: list[list[int]]) -> list[int]", "description": "Directed edges [u,v] mean u before v; return lexicographically smallest valid topological order of nodes 0..n-1, or [] if a cycle.", "notes": "", "tags": [ "graphs", "heap" ], "examples": [ { "case_id": "PY100-M14-T01", "input": [ 4, [ [ 0, 2 ], [ 1, 2 ] ] ], "expected": [ 0, 1, 2, 3 ] }, { "case_id": "PY100-M14-T02", "input": [ 3, [ [ 0, 1 ], [ 1, 2 ] ] ], "expected": [ 0, 1, 2 ] } ], "tests": [ { "case_id": "PY100-M14-T01", "input": [ 4, [ [ 0, 2 ], [ 1, 2 ] ] ], "expected": [ 0, 1, 2, 3 ] }, { "case_id": "PY100-M14-T02", "input": [ 3, [ [ 0, 1 ], [ 1, 2 ] ] ], "expected": [ 0, 1, 2 ] }, { "case_id": "PY100-M14-T03", "input": [ 2, [ [ 0, 1 ], [ 1, 0 ] ] ], "expected": [] }, { "case_id": "PY100-M14-T04", "input": [ 0, [] ], "expected": [] }, { "case_id": "PY100-M14-T05", "input": [ 4, [] ], "expected": [ 0, 1, 2, 3 ] }, { "case_id": "PY100-M14-T06", "input": [ 5, [ [ 2, 3 ], [ 3, 4 ], [ 1, 4 ] ] ], "expected": [ 0, 1, 2, 3, 4 ] } ] }, { "id": "PY100-M15", "difficulty": "medium", "slug": "island_count", "function_name": "island_count", "signature": "island_count(grid: list[str]) -> int", "description": "Rectangular grid of 0 and 1 characters. Count four-directionally connected components of 1 cells.", "notes": "", "tags": [ "graphs", "grid" ], "examples": [ { "case_id": "PY100-M15-T01", "input": [ [ "110", "010", "001" ] ], "expected": 2 }, { "case_id": "PY100-M15-T02", "input": [ [ "111", "111" ] ], "expected": 1 } ], "tests": [ { "case_id": "PY100-M15-T01", "input": [ [ "110", "010", "001" ] ], "expected": 2 }, { "case_id": "PY100-M15-T02", "input": [ [ "111", "111" ] ], "expected": 1 }, { "case_id": "PY100-M15-T03", "input": [ [ "000", "000" ] ], "expected": 0 }, { "case_id": "PY100-M15-T04", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-M15-T05", "input": [ [ "1" ] ], "expected": 1 }, { "case_id": "PY100-M15-T06", "input": [ [ "10101" ] ], "expected": 3 } ] }, { "id": "PY100-M16", "difficulty": "medium", "slug": "flood_fill", "function_name": "flood_fill", "signature": "flood_fill(grid: list[list[int]], sr: int, sc: int, new_color: int) -> list[list[int]]", "description": "Replace the four-connected component containing (sr,sc) with new_color; grid nonempty and coordinates valid.", "notes": "", "tags": [ "grid" ], "examples": [ { "case_id": "PY100-M16-T01", "input": [ [ [ 1, 1, 1 ], [ 1, 1, 0 ], [ 1, 0, 1 ] ], 1, 1, 2 ], "expected": [ [ 2, 2, 2 ], [ 2, 2, 0 ], [ 2, 0, 1 ] ] }, { "case_id": "PY100-M16-T02", "input": [ [ [ 0 ] ], 0, 0, 1 ], "expected": [ [ 1 ] ] } ], "tests": [ { "case_id": "PY100-M16-T01", "input": [ [ [ 1, 1, 1 ], [ 1, 1, 0 ], [ 1, 0, 1 ] ], 1, 1, 2 ], "expected": [ [ 2, 2, 2 ], [ 2, 2, 0 ], [ 2, 0, 1 ] ] }, { "case_id": "PY100-M16-T02", "input": [ [ [ 0 ] ], 0, 0, 1 ], "expected": [ [ 1 ] ] }, { "case_id": "PY100-M16-T03", "input": [ [ [ 1, 2 ], [ 2, 1 ] ], 0, 0, 3 ], "expected": [ [ 3, 2 ], [ 2, 1 ] ] }, { "case_id": "PY100-M16-T04", "input": [ [ [ 1, 1 ] ], 0, 1, 1 ], "expected": [ [ 1, 1 ] ] }, { "case_id": "PY100-M16-T05", "input": [ [ [ 2, 2 ], [ 2, 3 ] ], 1, 1, 8 ], "expected": [ [ 2, 2 ], [ 2, 8 ] ] }, { "case_id": "PY100-M16-T06", "input": [ [ [ 0, 0 ], [ 0, 0 ] ], 0, 0, 5 ], "expected": [ [ 5, 5 ], [ 5, 5 ] ] } ] }, { "id": "PY100-M17", "difficulty": "medium", "slug": "shortest_binary_grid", "function_name": "shortest_binary_grid", "signature": "shortest_binary_grid(grid: list[list[int]]) -> int", "description": "Find minimum four-directional moves from top-left to bottom-right through 0 cells (1 blocked); -1 if impossible.", "notes": "", "tags": [ "graphs", "bfs" ], "examples": [ { "case_id": "PY100-M17-T01", "input": [ [ [ 0, 0 ], [ 1, 0 ] ] ], "expected": 2 }, { "case_id": "PY100-M17-T02", "input": [ [ [ 0 ] ] ], "expected": 0 } ], "tests": [ { "case_id": "PY100-M17-T01", "input": [ [ [ 0, 0 ], [ 1, 0 ] ] ], "expected": 2 }, { "case_id": "PY100-M17-T02", "input": [ [ [ 0 ] ] ], "expected": 0 }, { "case_id": "PY100-M17-T03", "input": [ [ [ 1 ] ] ], "expected": -1 }, { "case_id": "PY100-M17-T04", "input": [ [ [ 0, 1 ], [ 1, 0 ] ] ], "expected": -1 }, { "case_id": "PY100-M17-T05", "input": [ [ [ 0, 0, 0 ], [ 1, 1, 0 ], [ 0, 0, 0 ] ] ], "expected": 4 }, { "case_id": "PY100-M17-T06", "input": [ [ [ 0, 0 ], [ 0, 1 ] ] ], "expected": -1 } ] }, { "id": "PY100-M18", "difficulty": "medium", "slug": "component_sizes", "function_name": "component_sizes", "signature": "component_sizes(n: int, edges: list[list[int]]) -> list[int]", "description": "Undirected graph on nodes 0..n-1; return connected component sizes sorted ascending, counting isolated nodes.", "notes": "", "tags": [ "graphs" ], "examples": [ { "case_id": "PY100-M18-T01", "input": [ 5, [ [ 0, 1 ], [ 1, 2 ], [ 3, 4 ] ] ], "expected": [ 2, 3 ] }, { "case_id": "PY100-M18-T02", "input": [ 3, [] ], "expected": [ 1, 1, 1 ] } ], "tests": [ { "case_id": "PY100-M18-T01", "input": [ 5, [ [ 0, 1 ], [ 1, 2 ], [ 3, 4 ] ] ], "expected": [ 2, 3 ] }, { "case_id": "PY100-M18-T02", "input": [ 3, [] ], "expected": [ 1, 1, 1 ] }, { "case_id": "PY100-M18-T03", "input": [ 0, [] ], "expected": [] }, { "case_id": "PY100-M18-T04", "input": [ 4, [ [ 0, 1 ], [ 1, 2 ], [ 2, 3 ] ] ], "expected": [ 4 ] }, { "case_id": "PY100-M18-T05", "input": [ 4, [ [ 0, 1 ], [ 0, 1 ] ] ], "expected": [ 1, 1, 2 ] }, { "case_id": "PY100-M18-T06", "input": [ 6, [ [ 1, 2 ], [ 3, 4 ] ] ], "expected": [ 1, 1, 2, 2 ] } ] }, { "id": "PY100-M19", "difficulty": "medium", "slug": "valid_sudoku_partial", "function_name": "valid_sudoku_partial", "signature": "valid_sudoku_partial(board: list[str]) -> bool", "description": "9x9 rows of digits 1-9 or dots. Return whether every filled row, column, and 3x3 block has no duplicate digit.", "notes": "", "tags": [ "matrix" ], "examples": [ { "case_id": "PY100-M19-T01", "input": [ [ "53..7....", "6..195...", ".98....6.", "8...6...3", "4..8.3..1", "7...2...6", ".6....28.", "...419..5", "....8..79" ] ], "expected": true }, { "case_id": "PY100-M19-T02", "input": [ [ ".........", ".........", ".........", ".........", ".........", ".........", ".........", ".........", "........." ] ], "expected": true } ], "tests": [ { "case_id": "PY100-M19-T01", "input": [ [ "53..7....", "6..195...", ".98....6.", "8...6...3", "4..8.3..1", "7...2...6", ".6....28.", "...419..5", "....8..79" ] ], "expected": true }, { "case_id": "PY100-M19-T02", "input": [ [ ".........", ".........", ".........", ".........", ".........", ".........", ".........", ".........", "........." ] ], "expected": true }, { "case_id": "PY100-M19-T03", "input": [ [ "11.......", ".........", ".........", ".........", ".........", ".........", ".........", ".........", "........." ] ], "expected": false }, { "case_id": "PY100-M19-T04", "input": [ [ "1........", "1........", ".........", ".........", ".........", ".........", ".........", ".........", "........." ] ], "expected": false }, { "case_id": "PY100-M19-T05", "input": [ [ "1........", ".1.......", ".........", ".........", ".........", ".........", ".........", ".........", "........." ] ], "expected": false }, { "case_id": "PY100-M19-T06", "input": [ [ "123456789", "123456789", "123456789", "123456789", "123456789", "123456789", "123456789", "123456789", "123456789" ] ], "expected": false } ] }, { "id": "PY100-M20", "difficulty": "medium", "slug": "decode_digit_messages", "function_name": "decode_digit_messages", "signature": "decode_digit_messages(text: str) -> int", "description": "Count decodings of digit string using 1->A through 26->Z, no leading-zero codes. Empty string has 0 decodings.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-M20-T01", "input": [ "12" ], "expected": 2 }, { "case_id": "PY100-M20-T02", "input": [ "226" ], "expected": 3 } ], "tests": [ { "case_id": "PY100-M20-T01", "input": [ "12" ], "expected": 2 }, { "case_id": "PY100-M20-T02", "input": [ "226" ], "expected": 3 }, { "case_id": "PY100-M20-T03", "input": [ "06" ], "expected": 0 }, { "case_id": "PY100-M20-T04", "input": [ "" ], "expected": 0 }, { "case_id": "PY100-M20-T05", "input": [ "10" ], "expected": 1 }, { "case_id": "PY100-M20-T06", "input": [ "11106" ], "expected": 2 } ] }, { "id": "PY100-M21", "difficulty": "medium", "slug": "climb_one_two", "function_name": "climb_one_two", "signature": "climb_one_two(n: int) -> int", "description": "Return number of ways to climb n steps using jumps of 1 or 2. n=0 has one empty way.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-M21-T01", "input": [ 0 ], "expected": 1 }, { "case_id": "PY100-M21-T02", "input": [ 1 ], "expected": 1 } ], "tests": [ { "case_id": "PY100-M21-T01", "input": [ 0 ], "expected": 1 }, { "case_id": "PY100-M21-T02", "input": [ 1 ], "expected": 1 }, { "case_id": "PY100-M21-T03", "input": [ 2 ], "expected": 2 }, { "case_id": "PY100-M21-T04", "input": [ 3 ], "expected": 3 }, { "case_id": "PY100-M21-T05", "input": [ 5 ], "expected": 8 }, { "case_id": "PY100-M21-T06", "input": [ 20 ], "expected": 10946 } ] }, { "id": "PY100-M22", "difficulty": "medium", "slug": "min_coin_change", "function_name": "min_coin_change", "signature": "min_coin_change(coins: list[int], amount: int) -> int", "description": "Unlimited positive coin denominations; return minimum coins to reach nonnegative amount, or -1.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-M22-T01", "input": [ [ 1, 2, 5 ], 11 ], "expected": 3 }, { "case_id": "PY100-M22-T02", "input": [ [ 2 ], 3 ], "expected": -1 } ], "tests": [ { "case_id": "PY100-M22-T01", "input": [ [ 1, 2, 5 ], 11 ], "expected": 3 }, { "case_id": "PY100-M22-T02", "input": [ [ 2 ], 3 ], "expected": -1 }, { "case_id": "PY100-M22-T03", "input": [ [ 1 ], 0 ], "expected": 0 }, { "case_id": "PY100-M22-T04", "input": [ [], 0 ], "expected": 0 }, { "case_id": "PY100-M22-T05", "input": [ [], 4 ], "expected": -1 }, { "case_id": "PY100-M22-T06", "input": [ [ 3, 4 ], 6 ], "expected": 2 } ] }, { "id": "PY100-M23", "difficulty": "medium", "slug": "lis_length", "function_name": "lis_length", "signature": "lis_length(nums: list[int]) -> int", "description": "Length of a strictly increasing (not necessarily contiguous) subsequence. Equal values do not extend.", "notes": "", "tags": [ "dp", "binary-search" ], "examples": [ { "case_id": "PY100-M23-T01", "input": [ [ 10, 9, 2, 5, 3, 7, 101, 18 ] ], "expected": 4 }, { "case_id": "PY100-M23-T02", "input": [ [ 0, 1, 0, 3, 2, 3 ] ], "expected": 4 } ], "tests": [ { "case_id": "PY100-M23-T01", "input": [ [ 10, 9, 2, 5, 3, 7, 101, 18 ] ], "expected": 4 }, { "case_id": "PY100-M23-T02", "input": [ [ 0, 1, 0, 3, 2, 3 ] ], "expected": 4 }, { "case_id": "PY100-M23-T03", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-M23-T04", "input": [ [ 7, 7, 7 ] ], "expected": 1 }, { "case_id": "PY100-M23-T05", "input": [ [ -2, -1, 0 ] ], "expected": 3 }, { "case_id": "PY100-M23-T06", "input": [ [ 5, 4, 3, 2, 1 ] ], "expected": 1 } ] }, { "id": "PY100-M24", "difficulty": "medium", "slug": "edit_distance", "function_name": "edit_distance", "signature": "edit_distance(a: str, b: str) -> int", "description": "Minimum single-character insertions, deletions or substitutions to transform a into b.", "notes": "", "tags": [ "dp", "strings" ], "examples": [ { "case_id": "PY100-M24-T01", "input": [ "horse", "ros" ], "expected": 3 }, { "case_id": "PY100-M24-T02", "input": [ "intention", "execution" ], "expected": 5 } ], "tests": [ { "case_id": "PY100-M24-T01", "input": [ "horse", "ros" ], "expected": 3 }, { "case_id": "PY100-M24-T02", "input": [ "intention", "execution" ], "expected": 5 }, { "case_id": "PY100-M24-T03", "input": [ "", "abc" ], "expected": 3 }, { "case_id": "PY100-M24-T04", "input": [ "abc", "" ], "expected": 3 }, { "case_id": "PY100-M24-T05", "input": [ "same", "same" ], "expected": 0 }, { "case_id": "PY100-M24-T06", "input": [ "kitten", "sitting" ], "expected": 3 } ] }, { "id": "PY100-M25", "difficulty": "medium", "slug": "lcs_length", "function_name": "lcs_length", "signature": "lcs_length(a: str, b: str) -> int", "description": "Length of longest common subsequence, not necessarily contiguous.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-M25-T01", "input": [ "abcde", "ace" ], "expected": 3 }, { "case_id": "PY100-M25-T02", "input": [ "abc", "abc" ], "expected": 3 } ], "tests": [ { "case_id": "PY100-M25-T01", "input": [ "abcde", "ace" ], "expected": 3 }, { "case_id": "PY100-M25-T02", "input": [ "abc", "abc" ], "expected": 3 }, { "case_id": "PY100-M25-T03", "input": [ "abc", "def" ], "expected": 0 }, { "case_id": "PY100-M25-T04", "input": [ "", "abc" ], "expected": 0 }, { "case_id": "PY100-M25-T05", "input": [ "abba", "baba" ], "expected": 3 }, { "case_id": "PY100-M25-T06", "input": [ "abcd", "ad" ], "expected": 2 } ] }, { "id": "PY100-M26", "difficulty": "medium", "slug": "knapsack_01", "function_name": "knapsack_01", "signature": "knapsack_01(weights: list[int], values: list[int], capacity: int) -> int", "description": "Each item may be selected at most once, weight positive, value nonnegative; maximize total value within capacity.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-M26-T01", "input": [ [ 2, 3, 4 ], [ 4, 5, 6 ], 5 ], "expected": 9 }, { "case_id": "PY100-M26-T02", "input": [ [ 1, 2 ], [ 10, 1 ], 0 ], "expected": 0 } ], "tests": [ { "case_id": "PY100-M26-T01", "input": [ [ 2, 3, 4 ], [ 4, 5, 6 ], 5 ], "expected": 9 }, { "case_id": "PY100-M26-T02", "input": [ [ 1, 2 ], [ 10, 1 ], 0 ], "expected": 0 }, { "case_id": "PY100-M26-T03", "input": [ [], [], 5 ], "expected": 0 }, { "case_id": "PY100-M26-T04", "input": [ [ 4 ], [ 9 ], 4 ], "expected": 9 }, { "case_id": "PY100-M26-T05", "input": [ [ 4 ], [ 9 ], 3 ], "expected": 0 }, { "case_id": "PY100-M26-T06", "input": [ [ 1, 1, 1 ], [ 1, 2, 3 ], 2 ], "expected": 5 } ] }, { "id": "PY100-M27", "difficulty": "medium", "slug": "subset_sum_exists", "function_name": "subset_sum_exists", "signature": "subset_sum_exists(nums: list[int], target: int) -> bool", "description": "Determine whether any subset (including empty) sums to target; values may be negative.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-M27-T01", "input": [ [ 3, 34, 4, 12, 5, 2 ], 9 ], "expected": true }, { "case_id": "PY100-M27-T02", "input": [ [ 3, 34, 4, 12, 5, 2 ], 30 ], "expected": false } ], "tests": [ { "case_id": "PY100-M27-T01", "input": [ [ 3, 34, 4, 12, 5, 2 ], 9 ], "expected": true }, { "case_id": "PY100-M27-T02", "input": [ [ 3, 34, 4, 12, 5, 2 ], 30 ], "expected": false }, { "case_id": "PY100-M27-T03", "input": [ [], 0 ], "expected": true }, { "case_id": "PY100-M27-T04", "input": [ [], 1 ], "expected": false }, { "case_id": "PY100-M27-T05", "input": [ [ -3, 2, 5 ], -1 ], "expected": true }, { "case_id": "PY100-M27-T06", "input": [ [ 2, 2, 2 ], 4 ], "expected": true } ] }, { "id": "PY100-M28", "difficulty": "medium", "slug": "equal_partition", "function_name": "equal_partition", "signature": "equal_partition(nums: list[int]) -> bool", "description": "Nonnegative integers; return whether they can be split into two subsets of equal sum; empty list is true.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-M28-T01", "input": [ [ 1, 5, 11, 5 ] ], "expected": true }, { "case_id": "PY100-M28-T02", "input": [ [ 1, 2, 3, 5 ] ], "expected": false } ], "tests": [ { "case_id": "PY100-M28-T01", "input": [ [ 1, 5, 11, 5 ] ], "expected": true }, { "case_id": "PY100-M28-T02", "input": [ [ 1, 2, 3, 5 ] ], "expected": false }, { "case_id": "PY100-M28-T03", "input": [ [] ], "expected": true }, { "case_id": "PY100-M28-T04", "input": [ [ 0, 0 ] ], "expected": true }, { "case_id": "PY100-M28-T05", "input": [ [ 2, 2, 3, 5 ] ], "expected": false }, { "case_id": "PY100-M28-T06", "input": [ [ 1, 1 ] ], "expected": true } ] }, { "id": "PY100-M29", "difficulty": "medium", "slug": "largest_histogram_rectangle", "function_name": "largest_histogram_rectangle", "signature": "largest_histogram_rectangle(heights: list[int]) -> int", "description": "Unit-width histogram bars with nonnegative heights. Return maximum axis-aligned rectangle area within bars.", "notes": "", "tags": [ "stack" ], "examples": [ { "case_id": "PY100-M29-T01", "input": [ [ 2, 1, 5, 6, 2, 3 ] ], "expected": 10 }, { "case_id": "PY100-M29-T02", "input": [ [] ], "expected": 0 } ], "tests": [ { "case_id": "PY100-M29-T01", "input": [ [ 2, 1, 5, 6, 2, 3 ] ], "expected": 10 }, { "case_id": "PY100-M29-T02", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-M29-T03", "input": [ [ 2, 4 ] ], "expected": 4 }, { "case_id": "PY100-M29-T04", "input": [ [ 0, 0 ] ], "expected": 0 }, { "case_id": "PY100-M29-T05", "input": [ [ 5 ] ], "expected": 5 }, { "case_id": "PY100-M29-T06", "input": [ [ 2, 2, 2 ] ], "expected": 6 } ] }, { "id": "PY100-M30", "difficulty": "medium", "slug": "next_greater_right", "function_name": "next_greater_right", "signature": "next_greater_right(nums: list[int]) -> list[int]", "description": "For each element return first strictly greater value to its right, or -1.", "notes": "", "tags": [ "stack" ], "examples": [ { "case_id": "PY100-M30-T01", "input": [ [ 2, 1, 2, 4, 3 ] ], "expected": [ 4, 2, 4, -1, -1 ] }, { "case_id": "PY100-M30-T02", "input": [ [ 1, 2, 3 ] ], "expected": [ 2, 3, -1 ] } ], "tests": [ { "case_id": "PY100-M30-T01", "input": [ [ 2, 1, 2, 4, 3 ] ], "expected": [ 4, 2, 4, -1, -1 ] }, { "case_id": "PY100-M30-T02", "input": [ [ 1, 2, 3 ] ], "expected": [ 2, 3, -1 ] }, { "case_id": "PY100-M30-T03", "input": [ [] ], "expected": [] }, { "case_id": "PY100-M30-T04", "input": [ [ 3, 2, 1 ] ], "expected": [ -1, -1, -1 ] }, { "case_id": "PY100-M30-T05", "input": [ [ 2, 2, 3 ] ], "expected": [ 3, 3, -1 ] }, { "case_id": "PY100-M30-T06", "input": [ [ -3, -1, -2 ] ], "expected": [ -1, -1, -1 ] } ] }, { "id": "PY100-M31", "difficulty": "medium", "slug": "days_until_warmer", "function_name": "days_until_warmer", "signature": "days_until_warmer(temperatures: list[int]) -> list[int]", "description": "For each day return days until a strictly warmer future temperature, or 0.", "notes": "", "tags": [ "stack" ], "examples": [ { "case_id": "PY100-M31-T01", "input": [ [ 73, 74, 75, 71, 69, 72, 76, 73 ] ], "expected": [ 1, 1, 4, 2, 1, 1, 0, 0 ] }, { "case_id": "PY100-M31-T02", "input": [ [] ], "expected": [] } ], "tests": [ { "case_id": "PY100-M31-T01", "input": [ [ 73, 74, 75, 71, 69, 72, 76, 73 ] ], "expected": [ 1, 1, 4, 2, 1, 1, 0, 0 ] }, { "case_id": "PY100-M31-T02", "input": [ [] ], "expected": [] }, { "case_id": "PY100-M31-T03", "input": [ [ 30, 40, 50 ] ], "expected": [ 1, 1, 0 ] }, { "case_id": "PY100-M31-T04", "input": [ [ 50, 40, 30 ] ], "expected": [ 0, 0, 0 ] }, { "case_id": "PY100-M31-T05", "input": [ [ 20, 20, 21 ] ], "expected": [ 2, 1, 0 ] }, { "case_id": "PY100-M31-T06", "input": [ [ 90 ] ], "expected": [ 0 ] } ] }, { "id": "PY100-M32", "difficulty": "medium", "slug": "sorted_anagram_groups", "function_name": "sorted_anagram_groups", "signature": "sorted_anagram_groups(words: list[str]) -> list[list[str]]", "description": "Group exact-case anagrams; sort words within each group; sort groups by their first word alphabetically. Empty input returns [].", "notes": "", "tags": [ "hashmap" ], "examples": [ { "case_id": "PY100-M32-T01", "input": [ [ "eat", "tea", "tan", "ate", "nat", "bat" ] ], "expected": [ [ "ate", "eat", "tea" ], [ "bat" ], [ "nat", "tan" ] ] }, { "case_id": "PY100-M32-T02", "input": [ [] ], "expected": [] } ], "tests": [ { "case_id": "PY100-M32-T01", "input": [ [ "eat", "tea", "tan", "ate", "nat", "bat" ] ], "expected": [ [ "ate", "eat", "tea" ], [ "bat" ], [ "nat", "tan" ] ] }, { "case_id": "PY100-M32-T02", "input": [ [] ], "expected": [] }, { "case_id": "PY100-M32-T03", "input": [ [ "", "" ] ], "expected": [ [ "", "" ] ] }, { "case_id": "PY100-M32-T04", "input": [ [ "abc", "bca", "cab", "xyz" ] ], "expected": [ [ "abc", "bca", "cab" ], [ "xyz" ] ] }, { "case_id": "PY100-M32-T05", "input": [ [ "a", "A" ] ], "expected": [ [ "A" ], [ "a" ] ] }, { "case_id": "PY100-M32-T06", "input": [ [ "ab", "ba", "a", "b" ] ], "expected": [ [ "a" ], [ "ab", "ba" ], [ "b" ] ] } ] }, { "id": "PY100-M33", "difficulty": "medium", "slug": "top_k_frequent_words", "function_name": "top_k_frequent_words", "signature": "top_k_frequent_words(words: list[str], k: int) -> list[str]", "description": "Return at most k distinct words by descending frequency, breaking ties alphabetically; k>=0.", "notes": "", "tags": [ "hashmap", "sorting" ], "examples": [ { "case_id": "PY100-M33-T01", "input": [ [ "i", "love", "leetcode", "i", "love", "coding" ], 2 ], "expected": [ "i", "love" ] }, { "case_id": "PY100-M33-T02", "input": [ [ "b", "a", "b", "c", "a" ], 3 ], "expected": [ "a", "b", "c" ] } ], "tests": [ { "case_id": "PY100-M33-T01", "input": [ [ "i", "love", "leetcode", "i", "love", "coding" ], 2 ], "expected": [ "i", "love" ] }, { "case_id": "PY100-M33-T02", "input": [ [ "b", "a", "b", "c", "a" ], 3 ], "expected": [ "a", "b", "c" ] }, { "case_id": "PY100-M33-T03", "input": [ [], 2 ], "expected": [] }, { "case_id": "PY100-M33-T04", "input": [ [ "a" ], 0 ], "expected": [] }, { "case_id": "PY100-M33-T05", "input": [ [ "z", "y", "x" ], 2 ], "expected": [ "x", "y" ] }, { "case_id": "PY100-M33-T06", "input": [ [ "a", "a", "b" ], 5 ], "expected": [ "a", "b" ] } ] }, { "id": "PY100-M34", "difficulty": "medium", "slug": "simplify_unix_path", "function_name": "simplify_unix_path", "signature": "simplify_unix_path(path: str) -> str", "description": "Canonicalize absolute Unix path by collapsing repeated slashes, . and ..; root cannot be traversed above.", "notes": "", "tags": [ "stack", "strings" ], "examples": [ { "case_id": "PY100-M34-T01", "input": [ "/home/" ], "expected": "/home" }, { "case_id": "PY100-M34-T02", "input": [ "/../" ], "expected": "/" } ], "tests": [ { "case_id": "PY100-M34-T01", "input": [ "/home/" ], "expected": "/home" }, { "case_id": "PY100-M34-T02", "input": [ "/../" ], "expected": "/" }, { "case_id": "PY100-M34-T03", "input": [ "/home//foo/" ], "expected": "/home/foo" }, { "case_id": "PY100-M34-T04", "input": [ "/a/./b/../../c/" ], "expected": "/c" }, { "case_id": "PY100-M34-T05", "input": [ "/" ], "expected": "/" }, { "case_id": "PY100-M34-T06", "input": [ "/a/.../b" ], "expected": "/a/.../b" } ] }, { "id": "PY100-M35", "difficulty": "medium", "slug": "minimum_cover_window", "function_name": "minimum_cover_window", "signature": "minimum_cover_window(text: str, chars: str) -> str", "description": "Shortest substring containing every character of chars with multiplicity. Tie: earliest start. Return empty if impossible or chars empty.", "notes": "", "tags": [ "sliding-window" ], "examples": [ { "case_id": "PY100-M35-T01", "input": [ "ADOBECODEBANC", "ABC" ], "expected": "BANC" }, { "case_id": "PY100-M35-T02", "input": [ "a", "aa" ], "expected": "" } ], "tests": [ { "case_id": "PY100-M35-T01", "input": [ "ADOBECODEBANC", "ABC" ], "expected": "BANC" }, { "case_id": "PY100-M35-T02", "input": [ "a", "aa" ], "expected": "" }, { "case_id": "PY100-M35-T03", "input": [ "abc", "" ], "expected": "" }, { "case_id": "PY100-M35-T04", "input": [ "aaab", "aab" ], "expected": "aab" }, { "case_id": "PY100-M35-T05", "input": [ "abcbc", "bc" ], "expected": "bc" }, { "case_id": "PY100-M35-T06", "input": [ "xyzabc", "cb" ], "expected": "bc" } ] }, { "id": "PY100-M36", "difficulty": "medium", "slug": "valid_ipv4", "function_name": "valid_ipv4", "signature": "valid_ipv4(text: str) -> bool", "description": "Validate strict dotted-decimal IPv4: 4 segments each 0..255; no leading zero except literal 0; ASCII digits only.", "notes": "", "tags": [ "parsing" ], "examples": [ { "case_id": "PY100-M36-T01", "input": [ "192.168.0.1" ], "expected": true }, { "case_id": "PY100-M36-T02", "input": [ "01.2.3.4" ], "expected": false } ], "tests": [ { "case_id": "PY100-M36-T01", "input": [ "192.168.0.1" ], "expected": true }, { "case_id": "PY100-M36-T02", "input": [ "01.2.3.4" ], "expected": false }, { "case_id": "PY100-M36-T03", "input": [ "256.1.1.1" ], "expected": false }, { "case_id": "PY100-M36-T04", "input": [ "0.0.0.0" ], "expected": true }, { "case_id": "PY100-M36-T05", "input": [ "1.2.3" ], "expected": false }, { "case_id": "PY100-M36-T06", "input": [ "1.2.3.a" ], "expected": false } ] }, { "id": "PY100-M37", "difficulty": "medium", "slug": "compare_versions", "function_name": "compare_versions", "signature": "compare_versions(a: str, b: str) -> int", "description": "Dot-separated nonnegative integer version components; trailing zero components ignored. Return -1, 0 or 1.", "notes": "", "tags": [ "parsing" ], "examples": [ { "case_id": "PY100-M37-T01", "input": [ "1.01", "1.001" ], "expected": 0 }, { "case_id": "PY100-M37-T02", "input": [ "1.0", "1.0.0" ], "expected": 0 } ], "tests": [ { "case_id": "PY100-M37-T01", "input": [ "1.01", "1.001" ], "expected": 0 }, { "case_id": "PY100-M37-T02", "input": [ "1.0", "1.0.0" ], "expected": 0 }, { "case_id": "PY100-M37-T03", "input": [ "0.1", "1.1" ], "expected": -1 }, { "case_id": "PY100-M37-T04", "input": [ "1.2", "1.1.9" ], "expected": 1 }, { "case_id": "PY100-M37-T05", "input": [ "10.0", "2.9" ], "expected": 1 }, { "case_id": "PY100-M37-T06", "input": [ "1.0.1", "1" ], "expected": 1 } ] }, { "id": "PY100-M38", "difficulty": "medium", "slug": "evaluate_rpn", "function_name": "evaluate_rpn", "signature": "evaluate_rpn(tokens: list[str]) -> int", "description": "Evaluate valid Reverse Polish notation with +,-,*,/; integer division truncates toward zero; no division by zero.", "notes": "", "tags": [ "stack" ], "examples": [ { "case_id": "PY100-M38-T01", "input": [ [ "2", "1", "+", "3", "*" ] ], "expected": 9 }, { "case_id": "PY100-M38-T02", "input": [ [ "4", "13", "5", "/", "+" ] ], "expected": 6 } ], "tests": [ { "case_id": "PY100-M38-T01", "input": [ [ "2", "1", "+", "3", "*" ] ], "expected": 9 }, { "case_id": "PY100-M38-T02", "input": [ [ "4", "13", "5", "/", "+" ] ], "expected": 6 }, { "case_id": "PY100-M38-T03", "input": [ [ "-7", "2", "/" ] ], "expected": -3 }, { "case_id": "PY100-M38-T04", "input": [ [ "5" ] ], "expected": 5 }, { "case_id": "PY100-M38-T05", "input": [ [ "8", "3", "-", "2", "*" ] ], "expected": 10 }, { "case_id": "PY100-M38-T06", "input": [ [ "10", "6", "9", "3", "+", "-11", "*", "/", "*", "17", "+", "5", "+" ] ], "expected": 22 } ] }, { "id": "PY100-M39", "difficulty": "medium", "slug": "unique_permutations", "function_name": "unique_permutations", "signature": "unique_permutations(nums: list[int]) -> list[list[int]]", "description": "Return all distinct permutations sorted lexicographically, each permutation as a list. Input length <=7.", "notes": "", "tags": [ "backtracking" ], "examples": [ { "case_id": "PY100-M39-T01", "input": [ [ 1, 1, 2 ] ], "expected": [ [ 1, 1, 2 ], [ 1, 2, 1 ], [ 2, 1, 1 ] ] }, { "case_id": "PY100-M39-T02", "input": [ [ 1, 2, 3 ] ], "expected": [ [ 1, 2, 3 ], [ 1, 3, 2 ], [ 2, 1, 3 ], [ 2, 3, 1 ], [ 3, 1, 2 ], [ 3, 2, 1 ] ] } ], "tests": [ { "case_id": "PY100-M39-T01", "input": [ [ 1, 1, 2 ] ], "expected": [ [ 1, 1, 2 ], [ 1, 2, 1 ], [ 2, 1, 1 ] ] }, { "case_id": "PY100-M39-T02", "input": [ [ 1, 2, 3 ] ], "expected": [ [ 1, 2, 3 ], [ 1, 3, 2 ], [ 2, 1, 3 ], [ 2, 3, 1 ], [ 3, 1, 2 ], [ 3, 2, 1 ] ] }, { "case_id": "PY100-M39-T03", "input": [ [] ], "expected": [ [] ] }, { "case_id": "PY100-M39-T04", "input": [ [ 5 ] ], "expected": [ [ 5 ] ] }, { "case_id": "PY100-M39-T05", "input": [ [ 2, 2 ] ], "expected": [ [ 2, 2 ] ] }, { "case_id": "PY100-M39-T06", "input": [ [ 0, -1, 0 ] ], "expected": [ [ -1, 0, 0 ], [ 0, -1, 0 ], [ 0, 0, -1 ] ] } ] }, { "id": "PY100-M40", "difficulty": "medium", "slug": "combinations_k", "function_name": "combinations_k", "signature": "combinations_k(n: int, k: int) -> list[list[int]]", "description": "Generate lexicographically sorted k-element strictly increasing combinations from numbers 1..n; 0<=k<=n<=10.", "notes": "", "tags": [ "backtracking" ], "examples": [ { "case_id": "PY100-M40-T01", "input": [ 4, 2 ], "expected": [ [ 1, 2 ], [ 1, 3 ], [ 1, 4 ], [ 2, 3 ], [ 2, 4 ], [ 3, 4 ] ] }, { "case_id": "PY100-M40-T02", "input": [ 1, 1 ], "expected": [ [ 1 ] ] } ], "tests": [ { "case_id": "PY100-M40-T01", "input": [ 4, 2 ], "expected": [ [ 1, 2 ], [ 1, 3 ], [ 1, 4 ], [ 2, 3 ], [ 2, 4 ], [ 3, 4 ] ] }, { "case_id": "PY100-M40-T02", "input": [ 1, 1 ], "expected": [ [ 1 ] ] }, { "case_id": "PY100-M40-T03", "input": [ 3, 0 ], "expected": [ [] ] }, { "case_id": "PY100-M40-T04", "input": [ 0, 0 ], "expected": [ [] ] }, { "case_id": "PY100-M40-T05", "input": [ 5, 5 ], "expected": [ [ 1, 2, 3, 4, 5 ] ] }, { "case_id": "PY100-M40-T06", "input": [ 5, 1 ], "expected": [ [ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ] ] } ] }, { "id": "PY100-M41", "difficulty": "medium", "slug": "phone_keypad_words", "function_name": "phone_keypad_words", "signature": "phone_keypad_words(digits: str) -> list[str]", "description": "Digits 2..9; return phone keypad letter combinations in lexicographic order, or [] for empty input.", "notes": "", "tags": [ "backtracking" ], "examples": [ { "case_id": "PY100-M41-T01", "input": [ "23" ], "expected": [ "ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf" ] }, { "case_id": "PY100-M41-T02", "input": [ "" ], "expected": [] } ], "tests": [ { "case_id": "PY100-M41-T01", "input": [ "23" ], "expected": [ "ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf" ] }, { "case_id": "PY100-M41-T02", "input": [ "" ], "expected": [] }, { "case_id": "PY100-M41-T03", "input": [ "2" ], "expected": [ "a", "b", "c" ] }, { "case_id": "PY100-M41-T04", "input": [ "79" ], "expected": [ "pw", "px", "py", "pz", "qw", "qx", "qy", "qz", "rw", "rx", "ry", "rz", "sw", "sx", "sy", "sz" ] }, { "case_id": "PY100-M41-T05", "input": [ "222" ], "expected": [ "aaa", "aab", "aac", "aba", "abb", "abc", "aca", "acb", "acc", "baa", "bab", "bac", "bba", "bbb", "bbc", "bca", "bcb", "bcc", "caa", "cab", "cac", "cba", "cbb", "cbc", "cca", "ccb", "ccc" ] }, { "case_id": "PY100-M41-T06", "input": [ "" ], "expected": [] } ] }, { "id": "PY100-M42", "difficulty": "medium", "slug": "kth_largest_with_duplicates", "function_name": "kth_largest_with_duplicates", "signature": "kth_largest_with_duplicates(nums: list[int], k: int) -> int", "description": "Return kth largest element counting duplicates; 1<=k<=len(nums).", "notes": "", "tags": [ "sorting", "heap" ], "examples": [ { "case_id": "PY100-M42-T01", "input": [ [ 3, 2, 1, 5, 6, 4 ], 2 ], "expected": 5 }, { "case_id": "PY100-M42-T02", "input": [ [ 3, 2, 3, 1, 2, 4, 5, 5, 6 ], 4 ], "expected": 4 } ], "tests": [ { "case_id": "PY100-M42-T01", "input": [ [ 3, 2, 1, 5, 6, 4 ], 2 ], "expected": 5 }, { "case_id": "PY100-M42-T02", "input": [ [ 3, 2, 3, 1, 2, 4, 5, 5, 6 ], 4 ], "expected": 4 }, { "case_id": "PY100-M42-T03", "input": [ [ 1 ], 1 ], "expected": 1 }, { "case_id": "PY100-M42-T04", "input": [ [ 0, 0 ], 2 ], "expected": 0 }, { "case_id": "PY100-M42-T05", "input": [ [ -1, -5, -2 ], 3 ], "expected": -5 }, { "case_id": "PY100-M42-T06", "input": [ [ 9, 8, 7 ], 1 ], "expected": 9 } ] }, { "id": "PY100-M43", "difficulty": "medium", "slug": "k_closest_points", "function_name": "k_closest_points", "signature": "k_closest_points(points: list[list[int]], k: int) -> list[list[int]]", "description": "Return k points closest to origin by squared distance; break ties by x then y, preserving duplicates.", "notes": "", "tags": [ "heap", "geometry" ], "examples": [ { "case_id": "PY100-M43-T01", "input": [ [ [ 1, 3 ], [ -2, 2 ] ], 1 ], "expected": [ [ -2, 2 ] ] }, { "case_id": "PY100-M43-T02", "input": [ [ [ 3, 3 ], [ 5, -1 ], [ -2, 4 ] ], 2 ], "expected": [ [ 3, 3 ], [ -2, 4 ] ] } ], "tests": [ { "case_id": "PY100-M43-T01", "input": [ [ [ 1, 3 ], [ -2, 2 ] ], 1 ], "expected": [ [ -2, 2 ] ] }, { "case_id": "PY100-M43-T02", "input": [ [ [ 3, 3 ], [ 5, -1 ], [ -2, 4 ] ], 2 ], "expected": [ [ 3, 3 ], [ -2, 4 ] ] }, { "case_id": "PY100-M43-T03", "input": [ [], 0 ], "expected": [] }, { "case_id": "PY100-M43-T04", "input": [ [ [ 1, 0 ], [ -1, 0 ], [ 0, 1 ] ], 2 ], "expected": [ [ -1, 0 ], [ 0, 1 ] ] }, { "case_id": "PY100-M43-T05", "input": [ [ [ 0, 0 ] ], 1 ], "expected": [ [ 0, 0 ] ] }, { "case_id": "PY100-M43-T06", "input": [ [ [ 5, 5 ], [ 2, 2 ] ], 0 ], "expected": [] } ] }, { "id": "PY100-M44", "difficulty": "medium", "slug": "count_inversions", "function_name": "count_inversions", "signature": "count_inversions(nums: list[int]) -> int", "description": "Count pairs inums[j]. Equal elements do not count.", "notes": "", "tags": [ "divide-conquer" ], "examples": [ { "case_id": "PY100-M44-T01", "input": [ [ 2, 4, 1, 3, 5 ] ], "expected": 3 }, { "case_id": "PY100-M44-T02", "input": [ [] ], "expected": 0 } ], "tests": [ { "case_id": "PY100-M44-T01", "input": [ [ 2, 4, 1, 3, 5 ] ], "expected": 3 }, { "case_id": "PY100-M44-T02", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-M44-T03", "input": [ [ 1, 2, 3 ] ], "expected": 0 }, { "case_id": "PY100-M44-T04", "input": [ [ 3, 2, 1 ] ], "expected": 3 }, { "case_id": "PY100-M44-T05", "input": [ [ 1, 1, 1 ] ], "expected": 0 }, { "case_id": "PY100-M44-T06", "input": [ [ -1, -3, -2 ] ], "expected": 2 } ] }, { "id": "PY100-M45", "difficulty": "medium", "slug": "two_stock_transactions", "function_name": "two_stock_transactions", "signature": "two_stock_transactions(prices: list[int]) -> int", "description": "Max profit with at most two nonoverlapping buy-sell transactions; cannot hold two shares simultaneously.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-M45-T01", "input": [ [ 3, 3, 5, 0, 0, 3, 1, 4 ] ], "expected": 6 }, { "case_id": "PY100-M45-T02", "input": [ [ 1, 2, 3, 4, 5 ] ], "expected": 4 } ], "tests": [ { "case_id": "PY100-M45-T01", "input": [ [ 3, 3, 5, 0, 0, 3, 1, 4 ] ], "expected": 6 }, { "case_id": "PY100-M45-T02", "input": [ [ 1, 2, 3, 4, 5 ] ], "expected": 4 }, { "case_id": "PY100-M45-T03", "input": [ [ 7, 6, 4, 3, 1 ] ], "expected": 0 }, { "case_id": "PY100-M45-T04", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-M45-T05", "input": [ [ 1 ] ], "expected": 0 }, { "case_id": "PY100-M45-T06", "input": [ [ 2, 1, 2, 0, 1 ] ], "expected": 2 } ] }, { "id": "PY100-H01", "difficulty": "hard", "slug": "minimum_word_break", "function_name": "minimum_word_break", "signature": "minimum_word_break(text: str, dictionary: list[str]) -> int", "description": "Minimum number of nonempty dictionary words concatenated to form text exactly, with unlimited reuse; -1 if impossible, 0 for empty text.", "notes": "", "tags": [ "dp", "strings" ], "examples": [ { "case_id": "PY100-H01-T01", "input": [ "leetcode", [ "leet", "code" ] ], "expected": 2 }, { "case_id": "PY100-H01-T02", "input": [ "catsanddog", [ "cats", "cat", "and", "sand", "dog" ] ], "expected": 3 } ], "tests": [ { "case_id": "PY100-H01-T01", "input": [ "leetcode", [ "leet", "code" ] ], "expected": 2 }, { "case_id": "PY100-H01-T02", "input": [ "catsanddog", [ "cats", "cat", "and", "sand", "dog" ] ], "expected": 3 }, { "case_id": "PY100-H01-T03", "input": [ "catsandog", [ "cats", "dog", "sand", "and", "cat" ] ], "expected": -1 }, { "case_id": "PY100-H01-T04", "input": [ "", [] ], "expected": 0 }, { "case_id": "PY100-H01-T05", "input": [ "aaaaa", [ "a", "aa", "aaa" ] ], "expected": 2 }, { "case_id": "PY100-H01-T06", "input": [ "abc", [ "ab", "bc" ] ], "expected": -1 } ] }, { "id": "PY100-H02", "difficulty": "hard", "slug": "wildcard_match", "function_name": "wildcard_match", "signature": "wildcard_match(text: str, pattern: str) -> bool", "description": "Match entire text to wildcard pattern: ? matches one character, * matches any sequence including empty; all other characters literal.", "notes": "", "tags": [ "dp", "strings" ], "examples": [ { "case_id": "PY100-H02-T01", "input": [ "aa", "a" ], "expected": false }, { "case_id": "PY100-H02-T02", "input": [ "aa", "*" ], "expected": true } ], "tests": [ { "case_id": "PY100-H02-T01", "input": [ "aa", "a" ], "expected": false }, { "case_id": "PY100-H02-T02", "input": [ "aa", "*" ], "expected": true }, { "case_id": "PY100-H02-T03", "input": [ "cb", "?a" ], "expected": false }, { "case_id": "PY100-H02-T04", "input": [ "adceb", "*a*b" ], "expected": true }, { "case_id": "PY100-H02-T05", "input": [ "acdcb", "a*c?b" ], "expected": false }, { "case_id": "PY100-H02-T06", "input": [ "", "*" ], "expected": true } ] }, { "id": "PY100-H03", "difficulty": "hard", "slug": "simple_regex_fullmatch", "function_name": "simple_regex_fullmatch", "signature": "simple_regex_fullmatch(text: str, pattern: str) -> bool", "description": "Full match using . for any single character and * for zero or more of immediately preceding atom. Pattern guaranteed valid (no leading or consecutive *).", "notes": "", "tags": [ "dp", "strings" ], "examples": [ { "case_id": "PY100-H03-T01", "input": [ "aa", "a" ], "expected": false }, { "case_id": "PY100-H03-T02", "input": [ "aa", "a*" ], "expected": true } ], "tests": [ { "case_id": "PY100-H03-T01", "input": [ "aa", "a" ], "expected": false }, { "case_id": "PY100-H03-T02", "input": [ "aa", "a*" ], "expected": true }, { "case_id": "PY100-H03-T03", "input": [ "ab", ".*" ], "expected": true }, { "case_id": "PY100-H03-T04", "input": [ "aab", "c*a*b" ], "expected": true }, { "case_id": "PY100-H03-T05", "input": [ "mississippi", "mis*is*p*." ], "expected": false }, { "case_id": "PY100-H03-T06", "input": [ "", "a*" ], "expected": true } ] }, { "id": "PY100-H04", "difficulty": "hard", "slug": "count_distinct_subsequences", "function_name": "count_distinct_subsequences", "signature": "count_distinct_subsequences(source: str, target: str) -> int", "description": "Number of index-distinct subsequences of source exactly equal to target. Empty target has one subsequence.", "notes": "", "tags": [ "dp", "strings" ], "examples": [ { "case_id": "PY100-H04-T01", "input": [ "rabbbit", "rabbit" ], "expected": 3 }, { "case_id": "PY100-H04-T02", "input": [ "babgbag", "bag" ], "expected": 5 } ], "tests": [ { "case_id": "PY100-H04-T01", "input": [ "rabbbit", "rabbit" ], "expected": 3 }, { "case_id": "PY100-H04-T02", "input": [ "babgbag", "bag" ], "expected": 5 }, { "case_id": "PY100-H04-T03", "input": [ "", "" ], "expected": 1 }, { "case_id": "PY100-H04-T04", "input": [ "abc", "" ], "expected": 1 }, { "case_id": "PY100-H04-T05", "input": [ "", "a" ], "expected": 0 }, { "case_id": "PY100-H04-T06", "input": [ "aaaa", "aa" ], "expected": 6 } ] }, { "id": "PY100-H05", "difficulty": "hard", "slug": "count_palindrome_substrings", "function_name": "count_palindrome_substrings", "signature": "count_palindrome_substrings(text: str) -> int", "description": "Count all nonempty palindromic substrings by their positions (repeats count separately).", "notes": "", "tags": [ "dp", "strings" ], "examples": [ { "case_id": "PY100-H05-T01", "input": [ "abc" ], "expected": 3 }, { "case_id": "PY100-H05-T02", "input": [ "aaa" ], "expected": 6 } ], "tests": [ { "case_id": "PY100-H05-T01", "input": [ "abc" ], "expected": 3 }, { "case_id": "PY100-H05-T02", "input": [ "aaa" ], "expected": 6 }, { "case_id": "PY100-H05-T03", "input": [ "" ], "expected": 0 }, { "case_id": "PY100-H05-T04", "input": [ "abba" ], "expected": 6 }, { "case_id": "PY100-H05-T05", "input": [ "ababa" ], "expected": 9 }, { "case_id": "PY100-H05-T06", "input": [ "aA" ], "expected": 2 } ] }, { "id": "PY100-H06", "difficulty": "hard", "slug": "longest_palindrome_subsequence", "function_name": "longest_palindrome_subsequence", "signature": "longest_palindrome_subsequence(text: str) -> int", "description": "Length of longest palindromic subsequence, not necessarily contiguous.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-H06-T01", "input": [ "bbbab" ], "expected": 4 }, { "case_id": "PY100-H06-T02", "input": [ "cbbd" ], "expected": 2 } ], "tests": [ { "case_id": "PY100-H06-T01", "input": [ "bbbab" ], "expected": 4 }, { "case_id": "PY100-H06-T02", "input": [ "cbbd" ], "expected": 2 }, { "case_id": "PY100-H06-T03", "input": [ "" ], "expected": 0 }, { "case_id": "PY100-H06-T04", "input": [ "a" ], "expected": 1 }, { "case_id": "PY100-H06-T05", "input": [ "character" ], "expected": 5 }, { "case_id": "PY100-H06-T06", "input": [ "agbdba" ], "expected": 5 } ] }, { "id": "PY100-H07", "difficulty": "hard", "slug": "matrix_chain_min_cost", "function_name": "matrix_chain_min_cost", "signature": "matrix_chain_min_cost(dimensions: list[int]) -> int", "description": "n matrices have dimensions p[i] by p[i+1]. Return minimum scalar multiplication count over all parenthesizations. Positive dimensions, len>=2.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-H07-T01", "input": [ [ 10, 30, 5, 60 ] ], "expected": 4500 }, { "case_id": "PY100-H07-T02", "input": [ [ 40, 20, 30, 10, 30 ] ], "expected": 26000 } ], "tests": [ { "case_id": "PY100-H07-T01", "input": [ [ 10, 30, 5, 60 ] ], "expected": 4500 }, { "case_id": "PY100-H07-T02", "input": [ [ 40, 20, 30, 10, 30 ] ], "expected": 26000 }, { "case_id": "PY100-H07-T03", "input": [ [ 10, 20 ] ], "expected": 0 }, { "case_id": "PY100-H07-T04", "input": [ [ 1, 1, 1, 1 ] ], "expected": 2 }, { "case_id": "PY100-H07-T05", "input": [ [ 5, 10, 3, 12, 5, 50, 6 ] ], "expected": 2010 }, { "case_id": "PY100-H07-T06", "input": [ [ 30, 35, 15, 5, 10, 20, 25 ] ], "expected": 15125 } ] }, { "id": "PY100-H08", "difficulty": "hard", "slug": "burst_balloons_max", "function_name": "burst_balloons_max", "signature": "burst_balloons_max(nums: list[int]) -> int", "description": "Burst positive integer balloons in any order; coins = value of balloon times adjacent remaining values, boundary neighbors count as 1. Maximize coins.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-H08-T01", "input": [ [ 3, 1, 5, 8 ] ], "expected": 167 }, { "case_id": "PY100-H08-T02", "input": [ [ 1, 5 ] ], "expected": 10 } ], "tests": [ { "case_id": "PY100-H08-T01", "input": [ [ 3, 1, 5, 8 ] ], "expected": 167 }, { "case_id": "PY100-H08-T02", "input": [ [ 1, 5 ] ], "expected": 10 }, { "case_id": "PY100-H08-T03", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-H08-T04", "input": [ [ 1 ] ], "expected": 1 }, { "case_id": "PY100-H08-T05", "input": [ [ 2, 2, 2 ] ], "expected": 14 }, { "case_id": "PY100-H08-T06", "input": [ [ 1, 2, 3 ] ], "expected": 12 } ] }, { "id": "PY100-H09", "difficulty": "hard", "slug": "weighted_job_scheduling", "function_name": "weighted_job_scheduling", "signature": "weighted_job_scheduling(jobs: list[list[int]]) -> int", "description": "Each job [start,end,profit], start=0; choose nonoverlapping half-open jobs maximizing profit. End==next start allowed.", "notes": "", "tags": [ "dp", "binary-search" ], "examples": [ { "case_id": "PY100-H09-T01", "input": [ [ [ 1, 3, 50 ], [ 2, 4, 10 ], [ 3, 5, 40 ], [ 3, 6, 70 ] ] ], "expected": 120 }, { "case_id": "PY100-H09-T02", "input": [ [ [ 1, 2, 10 ], [ 2, 3, 20 ] ] ], "expected": 30 } ], "tests": [ { "case_id": "PY100-H09-T01", "input": [ [ [ 1, 3, 50 ], [ 2, 4, 10 ], [ 3, 5, 40 ], [ 3, 6, 70 ] ] ], "expected": 120 }, { "case_id": "PY100-H09-T02", "input": [ [ [ 1, 2, 10 ], [ 2, 3, 20 ] ] ], "expected": 30 }, { "case_id": "PY100-H09-T03", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-H09-T04", "input": [ [ [ 1, 5, 10 ], [ 2, 3, 5 ], [ 3, 4, 5 ] ] ], "expected": 10 }, { "case_id": "PY100-H09-T05", "input": [ [ [ 1, 2, 0 ] ] ], "expected": 0 }, { "case_id": "PY100-H09-T06", "input": [ [ [ 0, 2, 2 ], [ 1, 3, 3 ], [ 3, 4, 4 ] ] ], "expected": 7 } ] }, { "id": "PY100-H10", "difficulty": "hard", "slug": "minimum_jump_count", "function_name": "minimum_jump_count", "signature": "minimum_jump_count(nums: list[int]) -> int", "description": "nums[i] gives max forward jump length. Return minimum jumps from index 0 to last index, -1 if unreachable; empty list returns 0.", "notes": "", "tags": [ "greedy", "graphs" ], "examples": [ { "case_id": "PY100-H10-T01", "input": [ [ 2, 3, 1, 1, 4 ] ], "expected": 2 }, { "case_id": "PY100-H10-T02", "input": [ [ 3, 2, 1, 0, 4 ] ], "expected": -1 } ], "tests": [ { "case_id": "PY100-H10-T01", "input": [ [ 2, 3, 1, 1, 4 ] ], "expected": 2 }, { "case_id": "PY100-H10-T02", "input": [ [ 3, 2, 1, 0, 4 ] ], "expected": -1 }, { "case_id": "PY100-H10-T03", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-H10-T04", "input": [ [ 0 ] ], "expected": 0 }, { "case_id": "PY100-H10-T05", "input": [ [ 1, 1, 1, 1 ] ], "expected": 3 }, { "case_id": "PY100-H10-T06", "input": [ [ 2, 0, 0 ] ], "expected": 1 } ] }, { "id": "PY100-H11", "difficulty": "hard", "slug": "trap_rain_water", "function_name": "trap_rain_water", "signature": "trap_rain_water(heights: list[int]) -> int", "description": "Unit-width nonnegative bars; return total units of trapped rainwater.", "notes": "", "tags": [ "two-pointers" ], "examples": [ { "case_id": "PY100-H11-T01", "input": [ [ 0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1 ] ], "expected": 6 }, { "case_id": "PY100-H11-T02", "input": [ [ 4, 2, 0, 3, 2, 5 ] ], "expected": 9 } ], "tests": [ { "case_id": "PY100-H11-T01", "input": [ [ 0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1 ] ], "expected": 6 }, { "case_id": "PY100-H11-T02", "input": [ [ 4, 2, 0, 3, 2, 5 ] ], "expected": 9 }, { "case_id": "PY100-H11-T03", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-H11-T04", "input": [ [ 3, 3, 3 ] ], "expected": 0 }, { "case_id": "PY100-H11-T05", "input": [ [ 0, 1, 2, 3 ] ], "expected": 0 }, { "case_id": "PY100-H11-T06", "input": [ [ 3, 0, 3 ] ], "expected": 3 } ] }, { "id": "PY100-H12", "difficulty": "hard", "slug": "sliding_window_maximum", "function_name": "sliding_window_maximum", "signature": "sliding_window_maximum(nums: list[int], k: int) -> list[int]", "description": "Return maximum in every contiguous window of size k. nums nonempty, 1<=k<=len(nums).", "notes": "", "tags": [ "deque" ], "examples": [ { "case_id": "PY100-H12-T01", "input": [ [ 1, 3, -1, -3, 5, 3, 6, 7 ], 3 ], "expected": [ 3, 3, 5, 5, 6, 7 ] }, { "case_id": "PY100-H12-T02", "input": [ [ 1 ], 1 ], "expected": [ 1 ] } ], "tests": [ { "case_id": "PY100-H12-T01", "input": [ [ 1, 3, -1, -3, 5, 3, 6, 7 ], 3 ], "expected": [ 3, 3, 5, 5, 6, 7 ] }, { "case_id": "PY100-H12-T02", "input": [ [ 1 ], 1 ], "expected": [ 1 ] }, { "case_id": "PY100-H12-T03", "input": [ [ 9, 8, 7 ], 1 ], "expected": [ 9, 8, 7 ] }, { "case_id": "PY100-H12-T04", "input": [ [ 2, 2, 2 ], 2 ], "expected": [ 2, 2 ] }, { "case_id": "PY100-H12-T05", "input": [ [ -1, -5, -3 ], 3 ], "expected": [ -1 ] }, { "case_id": "PY100-H12-T06", "input": [ [ 4, 1, 7, 2 ], 2 ], "expected": [ 4, 7, 7 ] } ] }, { "id": "PY100-H13", "difficulty": "hard", "slug": "sliding_window_median", "function_name": "sliding_window_median", "signature": "sliding_window_median(nums: list[int], k: int) -> list[float]", "description": "Return median per contiguous size-k window. For even k use arithmetic mean of two middle numbers; results numerical.", "notes": "", "tags": [ "heap", "sorting" ], "examples": [ { "case_id": "PY100-H13-T01", "input": [ [ 1, 3, -1, -3, 5, 3, 6, 7 ], 3 ], "expected": [ 1, -1, -1, 3, 5, 6 ] }, { "case_id": "PY100-H13-T02", "input": [ [ 1, 2, 3, 4 ], 2 ], "expected": [ 1.5, 2.5, 3.5 ] } ], "tests": [ { "case_id": "PY100-H13-T01", "input": [ [ 1, 3, -1, -3, 5, 3, 6, 7 ], 3 ], "expected": [ 1, -1, -1, 3, 5, 6 ] }, { "case_id": "PY100-H13-T02", "input": [ [ 1, 2, 3, 4 ], 2 ], "expected": [ 1.5, 2.5, 3.5 ] }, { "case_id": "PY100-H13-T03", "input": [ [ 5 ], 1 ], "expected": [ 5 ] }, { "case_id": "PY100-H13-T04", "input": [ [ 0, 0, 0 ], 2 ], "expected": [ 0.0, 0.0 ] }, { "case_id": "PY100-H13-T05", "input": [ [ -2, -1, 0, 1 ], 4 ], "expected": [ -0.5 ] }, { "case_id": "PY100-H13-T06", "input": [ [ 9, 1, 8, 2, 7 ], 3 ], "expected": [ 8, 2, 7 ] } ] }, { "id": "PY100-H14", "difficulty": "hard", "slug": "kth_smallest_pair_distance", "function_name": "kth_smallest_pair_distance", "signature": "kth_smallest_pair_distance(nums: list[int], k: int) -> int", "description": "Among all unordered index pairs i=2, valid k.", "notes": "", "tags": [ "binary-search" ], "examples": [ { "case_id": "PY100-H14-T01", "input": [ [ 1, 3, 1 ], 1 ], "expected": 0 }, { "case_id": "PY100-H14-T02", "input": [ [ 1, 6, 1 ], 3 ], "expected": 5 } ], "tests": [ { "case_id": "PY100-H14-T01", "input": [ [ 1, 3, 1 ], 1 ], "expected": 0 }, { "case_id": "PY100-H14-T02", "input": [ [ 1, 6, 1 ], 3 ], "expected": 5 }, { "case_id": "PY100-H14-T03", "input": [ [ 1, 2 ], 1 ], "expected": 1 }, { "case_id": "PY100-H14-T04", "input": [ [ 0, 0, 0 ], 2 ], "expected": 0 }, { "case_id": "PY100-H14-T05", "input": [ [ -3, 1, 4 ], 2 ], "expected": 4 }, { "case_id": "PY100-H14-T06", "input": [ [ 1, 2, 3, 4 ], 4 ], "expected": 2 } ] }, { "id": "PY100-H15", "difficulty": "hard", "slug": "median_two_sorted", "function_name": "median_two_sorted", "signature": "median_two_sorted(a: list[int], b: list[int]) -> float", "description": "Both inputs sorted nondecreasing, combined length >=1. Return exact median, using arithmetic mean for even count.", "notes": "", "tags": [ "binary-search" ], "examples": [ { "case_id": "PY100-H15-T01", "input": [ [ 1, 3 ], [ 2 ] ], "expected": 2 }, { "case_id": "PY100-H15-T02", "input": [ [ 1, 2 ], [ 3, 4 ] ], "expected": 2.5 } ], "tests": [ { "case_id": "PY100-H15-T01", "input": [ [ 1, 3 ], [ 2 ] ], "expected": 2 }, { "case_id": "PY100-H15-T02", "input": [ [ 1, 2 ], [ 3, 4 ] ], "expected": 2.5 }, { "case_id": "PY100-H15-T03", "input": [ [], [ 1 ] ], "expected": 1 }, { "case_id": "PY100-H15-T04", "input": [ [ 0, 0 ], [ 0, 0 ] ], "expected": 0.0 }, { "case_id": "PY100-H15-T05", "input": [ [ -5, -1 ], [ -2, 0 ] ], "expected": -1.5 }, { "case_id": "PY100-H15-T06", "input": [ [ 1 ], [ 2, 3, 4 ] ], "expected": 2.5 } ] }, { "id": "PY100-H16", "difficulty": "hard", "slug": "count_smaller_to_right", "function_name": "count_smaller_to_right", "signature": "count_smaller_to_right(nums: list[int]) -> list[int]", "description": "For each index, count strictly smaller elements to its right, retaining original positions.", "notes": "", "tags": [ "fenwick", "divide-conquer" ], "examples": [ { "case_id": "PY100-H16-T01", "input": [ [ 5, 2, 6, 1 ] ], "expected": [ 2, 1, 1, 0 ] }, { "case_id": "PY100-H16-T02", "input": [ [] ], "expected": [] } ], "tests": [ { "case_id": "PY100-H16-T01", "input": [ [ 5, 2, 6, 1 ] ], "expected": [ 2, 1, 1, 0 ] }, { "case_id": "PY100-H16-T02", "input": [ [] ], "expected": [] }, { "case_id": "PY100-H16-T03", "input": [ [ 1, 1, 1 ] ], "expected": [ 0, 0, 0 ] }, { "case_id": "PY100-H16-T04", "input": [ [ 3, 2, 1 ] ], "expected": [ 2, 1, 0 ] }, { "case_id": "PY100-H16-T05", "input": [ [ -1, -2, -3 ] ], "expected": [ 2, 1, 0 ] }, { "case_id": "PY100-H16-T06", "input": [ [ 2, 0, 1 ] ], "expected": [ 2, 0, 0 ] } ] }, { "id": "PY100-H17", "difficulty": "hard", "slug": "single_source_shortest_paths", "function_name": "single_source_shortest_paths", "signature": "single_source_shortest_paths(n: int, edges: list[list[int]], source: int) -> list[int]", "description": "Directed weighted edges [u,v,w] with nonnegative integer weights; shortest path from source to each node, -1 if unreachable.", "notes": "", "tags": [ "graphs", "dijkstra" ], "examples": [ { "case_id": "PY100-H17-T01", "input": [ 5, [ [ 0, 1, 2 ], [ 1, 2, 3 ], [ 0, 3, 1 ], [ 3, 2, 1 ] ], 0 ], "expected": [ 0, 2, 2, 1, -1 ] }, { "case_id": "PY100-H17-T02", "input": [ 3, [], 0 ], "expected": [ 0, -1, -1 ] } ], "tests": [ { "case_id": "PY100-H17-T01", "input": [ 5, [ [ 0, 1, 2 ], [ 1, 2, 3 ], [ 0, 3, 1 ], [ 3, 2, 1 ] ], 0 ], "expected": [ 0, 2, 2, 1, -1 ] }, { "case_id": "PY100-H17-T02", "input": [ 3, [], 0 ], "expected": [ 0, -1, -1 ] }, { "case_id": "PY100-H17-T03", "input": [ 1, [], 0 ], "expected": [ 0 ] }, { "case_id": "PY100-H17-T04", "input": [ 3, [ [ 0, 1, 0 ], [ 1, 2, 0 ] ], 0 ], "expected": [ 0, 0, 0 ] }, { "case_id": "PY100-H17-T05", "input": [ 4, [ [ 0, 1, 10 ], [ 0, 2, 1 ], [ 2, 1, 2 ] ], 0 ], "expected": [ 0, 3, 1, -1 ] }, { "case_id": "PY100-H17-T06", "input": [ 2, [ [ 1, 0, 5 ] ], 1 ], "expected": [ 5, 0 ] } ] }, { "id": "PY100-H18", "difficulty": "hard", "slug": "flight_with_stops", "function_name": "flight_with_stops", "signature": "flight_with_stops(n: int, flights: list[list[int]], src: int, dst: int, max_stops: int) -> int", "description": "Directed flights [u,v,cost] with positive costs. Minimum fare from src to dst using at most max_stops intermediate cities (at most max_stops+1 edges), or -1.", "notes": "", "tags": [ "graphs", "dp" ], "examples": [ { "case_id": "PY100-H18-T01", "input": [ 4, [ [ 0, 1, 100 ], [ 1, 2, 100 ], [ 2, 3, 100 ], [ 0, 3, 500 ] ], 0, 3, 1 ], "expected": 500 }, { "case_id": "PY100-H18-T02", "input": [ 4, [ [ 0, 1, 100 ], [ 1, 2, 100 ], [ 2, 3, 100 ], [ 0, 3, 500 ] ], 0, 3, 2 ], "expected": 300 } ], "tests": [ { "case_id": "PY100-H18-T01", "input": [ 4, [ [ 0, 1, 100 ], [ 1, 2, 100 ], [ 2, 3, 100 ], [ 0, 3, 500 ] ], 0, 3, 1 ], "expected": 500 }, { "case_id": "PY100-H18-T02", "input": [ 4, [ [ 0, 1, 100 ], [ 1, 2, 100 ], [ 2, 3, 100 ], [ 0, 3, 500 ] ], 0, 3, 2 ], "expected": 300 }, { "case_id": "PY100-H18-T03", "input": [ 3, [ [ 0, 1, 100 ], [ 1, 2, 100 ], [ 0, 2, 500 ] ], 0, 2, 0 ], "expected": 500 }, { "case_id": "PY100-H18-T04", "input": [ 3, [], 0, 2, 2 ], "expected": -1 }, { "case_id": "PY100-H18-T05", "input": [ 1, [], 0, 0, 0 ], "expected": 0 }, { "case_id": "PY100-H18-T06", "input": [ 3, [ [ 0, 1, 1 ], [ 1, 0, 1 ], [ 1, 2, 1 ] ], 0, 2, 1 ], "expected": 2 } ] }, { "id": "PY100-H19", "difficulty": "hard", "slug": "shortest_walk_visit_all", "function_name": "shortest_walk_visit_all", "signature": "shortest_walk_visit_all(n: int, edges: list[list[int]]) -> int", "description": "Undirected graph nodes 0..n-1, n<=10. Start anywhere; shortest walk visiting all nodes at least once, repeating allowed; -1 if disconnected.", "notes": "", "tags": [ "graphs", "bitmask" ], "examples": [ { "case_id": "PY100-H19-T01", "input": [ 4, [ [ 0, 1 ], [ 0, 2 ], [ 0, 3 ] ] ], "expected": 4 }, { "case_id": "PY100-H19-T02", "input": [ 5, [ [ 0, 1 ], [ 1, 2 ], [ 2, 3 ], [ 3, 4 ] ] ], "expected": 4 } ], "tests": [ { "case_id": "PY100-H19-T01", "input": [ 4, [ [ 0, 1 ], [ 0, 2 ], [ 0, 3 ] ] ], "expected": 4 }, { "case_id": "PY100-H19-T02", "input": [ 5, [ [ 0, 1 ], [ 1, 2 ], [ 2, 3 ], [ 3, 4 ] ] ], "expected": 4 }, { "case_id": "PY100-H19-T03", "input": [ 1, [] ], "expected": 0 }, { "case_id": "PY100-H19-T04", "input": [ 3, [] ], "expected": -1 }, { "case_id": "PY100-H19-T05", "input": [ 4, [ [ 0, 1 ], [ 1, 2 ], [ 2, 3 ], [ 3, 0 ] ] ], "expected": 3 }, { "case_id": "PY100-H19-T06", "input": [ 2, [ [ 0, 1 ] ] ], "expected": 1 } ] }, { "id": "PY100-H20", "difficulty": "hard", "slug": "min_grid_path_sum", "function_name": "min_grid_path_sum", "signature": "min_grid_path_sum(grid: list[list[int]]) -> int", "description": "Nonempty rectangular nonnegative grid. Start top-left, move only right/down; minimum sum including endpoints.", "notes": "", "tags": [ "dp", "grid" ], "examples": [ { "case_id": "PY100-H20-T01", "input": [ [ [ 1, 3, 1 ], [ 1, 5, 1 ], [ 4, 2, 1 ] ] ], "expected": 7 }, { "case_id": "PY100-H20-T02", "input": [ [ [ 1, 2, 3 ], [ 4, 5, 6 ] ] ], "expected": 12 } ], "tests": [ { "case_id": "PY100-H20-T01", "input": [ [ [ 1, 3, 1 ], [ 1, 5, 1 ], [ 4, 2, 1 ] ] ], "expected": 7 }, { "case_id": "PY100-H20-T02", "input": [ [ [ 1, 2, 3 ], [ 4, 5, 6 ] ] ], "expected": 12 }, { "case_id": "PY100-H20-T03", "input": [ [ [ 5 ] ] ], "expected": 5 }, { "case_id": "PY100-H20-T04", "input": [ [ [ 0, 0 ], [ 0, 0 ] ] ], "expected": 0 }, { "case_id": "PY100-H20-T05", "input": [ [ [ 1, 9, 1 ] ] ], "expected": 11 }, { "case_id": "PY100-H20-T06", "input": [ [ [ 2 ], [ 3 ], [ 4 ] ] ], "expected": 9 } ] }, { "id": "PY100-H21", "difficulty": "hard", "slug": "unique_paths_obstacles", "function_name": "unique_paths_obstacles", "signature": "unique_paths_obstacles(grid: list[list[int]]) -> int", "description": "Rectangular grid 0 open, 1 blocked. Count paths top-left to bottom-right moving only right/down, avoiding blocked cells.", "notes": "", "tags": [ "dp", "grid" ], "examples": [ { "case_id": "PY100-H21-T01", "input": [ [ [ 0, 0, 0 ], [ 0, 1, 0 ], [ 0, 0, 0 ] ] ], "expected": 2 }, { "case_id": "PY100-H21-T02", "input": [ [ [ 0, 1 ], [ 0, 0 ] ] ], "expected": 1 } ], "tests": [ { "case_id": "PY100-H21-T01", "input": [ [ [ 0, 0, 0 ], [ 0, 1, 0 ], [ 0, 0, 0 ] ] ], "expected": 2 }, { "case_id": "PY100-H21-T02", "input": [ [ [ 0, 1 ], [ 0, 0 ] ] ], "expected": 1 }, { "case_id": "PY100-H21-T03", "input": [ [ [ 1 ] ] ], "expected": 0 }, { "case_id": "PY100-H21-T04", "input": [ [ [ 0 ] ] ], "expected": 1 }, { "case_id": "PY100-H21-T05", "input": [ [ [ 0, 0 ], [ 0, 0 ] ] ], "expected": 2 }, { "case_id": "PY100-H21-T06", "input": [ [ [ 0, 0 ], [ 1, 1 ] ] ], "expected": 0 } ] }, { "id": "PY100-H22", "difficulty": "hard", "slug": "maximal_one_rectangle", "function_name": "maximal_one_rectangle", "signature": "maximal_one_rectangle(grid: list[str]) -> int", "description": "Rectangular rows of characters 0/1, find largest area rectangle consisting only of 1 cells.", "notes": "", "tags": [ "stack", "dp" ], "examples": [ { "case_id": "PY100-H22-T01", "input": [ [ "10100", "10111", "11111", "10010" ] ], "expected": 6 }, { "case_id": "PY100-H22-T02", "input": [ [ "0" ] ], "expected": 0 } ], "tests": [ { "case_id": "PY100-H22-T01", "input": [ [ "10100", "10111", "11111", "10010" ] ], "expected": 6 }, { "case_id": "PY100-H22-T02", "input": [ [ "0" ] ], "expected": 0 }, { "case_id": "PY100-H22-T03", "input": [ [ "1" ] ], "expected": 1 }, { "case_id": "PY100-H22-T04", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-H22-T05", "input": [ [ "111", "111" ] ], "expected": 6 }, { "case_id": "PY100-H22-T06", "input": [ [ "101", "010", "101" ] ], "expected": 1 } ] }, { "id": "PY100-H23", "difficulty": "hard", "slug": "palindrome_partition_cuts", "function_name": "palindrome_partition_cuts", "signature": "palindrome_partition_cuts(text: str) -> int", "description": "Minimum cuts dividing string into nonempty palindromic substrings; empty text requires zero cuts.", "notes": "", "tags": [ "dp", "strings" ], "examples": [ { "case_id": "PY100-H23-T01", "input": [ "aab" ], "expected": 1 }, { "case_id": "PY100-H23-T02", "input": [ "a" ], "expected": 0 } ], "tests": [ { "case_id": "PY100-H23-T01", "input": [ "aab" ], "expected": 1 }, { "case_id": "PY100-H23-T02", "input": [ "a" ], "expected": 0 }, { "case_id": "PY100-H23-T03", "input": [ "ab" ], "expected": 1 }, { "case_id": "PY100-H23-T04", "input": [ "" ], "expected": 0 }, { "case_id": "PY100-H23-T05", "input": [ "abba" ], "expected": 0 }, { "case_id": "PY100-H23-T06", "input": [ "abcbaef" ], "expected": 2 } ] }, { "id": "PY100-H24", "difficulty": "hard", "slug": "maximal_one_square", "function_name": "maximal_one_square", "signature": "maximal_one_square(grid: list[str]) -> int", "description": "Rectangular binary character grid; area of largest all-1 square (0 if none).", "notes": "", "tags": [ "dp", "matrix" ], "examples": [ { "case_id": "PY100-H24-T01", "input": [ [ "10100", "10111", "11111", "10010" ] ], "expected": 4 }, { "case_id": "PY100-H24-T02", "input": [ [ "0" ] ], "expected": 0 } ], "tests": [ { "case_id": "PY100-H24-T01", "input": [ [ "10100", "10111", "11111", "10010" ] ], "expected": 4 }, { "case_id": "PY100-H24-T02", "input": [ [ "0" ] ], "expected": 0 }, { "case_id": "PY100-H24-T03", "input": [ [ "1" ] ], "expected": 1 }, { "case_id": "PY100-H24-T04", "input": [ [] ], "expected": 0 }, { "case_id": "PY100-H24-T05", "input": [ [ "111", "111", "111" ] ], "expected": 9 }, { "case_id": "PY100-H24-T06", "input": [ [ "101", "010", "101" ] ], "expected": 1 } ] }, { "id": "PY100-H25", "difficulty": "hard", "slug": "minimum_stick_cut_cost", "function_name": "minimum_stick_cut_cost", "signature": "minimum_stick_cut_cost(length: int, cuts: list[int]) -> int", "description": "Stick from 0 to length, distinct interior cut positions. Cost per cut is current segment length. Find minimum total cost.", "notes": "", "tags": [ "dp" ], "examples": [ { "case_id": "PY100-H25-T01", "input": [ 7, [ 1, 3, 4, 5 ] ], "expected": 16 }, { "case_id": "PY100-H25-T02", "input": [ 9, [ 5, 6, 1, 4, 2 ] ], "expected": 22 } ], "tests": [ { "case_id": "PY100-H25-T01", "input": [ 7, [ 1, 3, 4, 5 ] ], "expected": 16 }, { "case_id": "PY100-H25-T02", "input": [ 9, [ 5, 6, 1, 4, 2 ] ], "expected": 22 }, { "case_id": "PY100-H25-T03", "input": [ 10, [] ], "expected": 0 }, { "case_id": "PY100-H25-T04", "input": [ 2, [ 1 ] ], "expected": 2 }, { "case_id": "PY100-H25-T05", "input": [ 100, [ 50 ] ], "expected": 100 }, { "case_id": "PY100-H25-T06", "input": [ 6, [ 2, 4 ] ], "expected": 10 } ] } ]