# LeetCode 22. Generate Parentheses

Description https://leetcode.com/problems/generate-parentheses/ Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. For example, given n = 3, a…

# LeetCode 49. Group Anagrams

Description https://leetcode.com/problems/group-anagrams/ Given an array of strings, group anagrams together. Example: Input: [“eat”, “tea”, “tan”, “ate”, “nat”, “bat”], Output: […

# LeetCode 38. Count and Say

Description https://leetcode.com/problems/count-and-say/ The count-and-say sequence is the sequence of integers with the first five terms as following: 1. 1 2.…

# LeetCode 242. Valid Anagram

Description https://leetcode.com/problems/valid-anagram/ Given two strings s and t , write a function to determine if t is an anagram of s. Example 1: Input: s = “anagram”,…

# LeetCode 125. Valid Palindrome

Description https://leetcode.com/problems/valid-palindrome/ Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. Note: For the…

# LeetCode 344. Reverse String

Description https://leetcode.com/problems/reverse-string/ Write a function that reverses a string. The input string is given as an array of characters char[]. Do…

# LeetCode 387. First Unique Character in a String

Description Given a string, find the first non-repeating character in it and return it’s index. If it doesn’t exist, return…

# LeetCode 14. Longest Common Prefix

Description https://leetcode.com/problems/longest-common-prefix/description/ Write a function to find the longest common prefix string amongst an array of strings. If there is…

# LeetCode 12. Integer to Roman

Description https://leetcode.com/problems/integer-to-roman/ Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from…

# LeetCode 8. String to Integer (atoi)

Description https://leetcode.com/problems/string-to-integer-atoi/ Implement atoi which converts a string to an integer. The function first discards as many whitespace characters as necessary until the…