James Pan

原题网址：https://leetcode.com/problems/find-peak-element/ A peak element is an element that is greater than its neighbors. Given an input array where num[i] ≠ num[i+1], find a peak element and ret

原题网址：https://leetcode.com/problems/longest-valid-parentheses/ Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring