a7895906的博客

原题：You are given an n x n 2D matrix representing an image.Rotate the image by 90 degrees (clockwise).Follow up:Could you do this in-place?题意就不多说了，比较经典的一个问题，90度顺时针旋转一个n*n的二维矩阵，难点在于只能使

原题：Given an array of integers, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the two numbers such that they add up to the targ

原题：Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.题意：给定一个数组num，求数组中三个数字相加为0的所有组合