摘要:
Given an array of integers, every element appears twice except for one. Find that single one. 这道题看似很简单,但是需要线性时间和不消耗额外空间,这里需要用到c++的“亦或”操作,因为 相同数数字 ^ 操作 阅读全文
摘要:
You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you cl 阅读全文
摘要:
Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining. 阅读全文