摘要：
https://oj.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] 阅读全文
摘要：
https://oj.leetcode.com/problems/permutations/Given a collection of numbers, return all possible permutations.For example,[1,2,3]have the following pe... 阅读全文