Easy
Solutions and thought process for easy difficulty Leetcode problems.
Easy
20. Valid Parentheses
Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
#stack
Easy
125. Valid Palindrome
A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric characters include letters and numbers.
#two-pointers