摘要：
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?来源： https://leetcode.com/problems/rotate-image/分析方法1：关键在于找到旋转90°的... 阅读全文
摘要：
Given a collection of numbers that might contain duplicates, return all possible unique permutations.For example,[1,1,2] have the following unique permutations:[ [1,1,2], [1,2,1], [2,1,1] ] 来源： ... 阅读全文
摘要：
Given a collection of distinct numbers, return all possible permutations.For example,[1,2,3] have the following permutations:[ [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1] ]来源： htt... 阅读全文
摘要：
Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2.Note:The length of both num1 and num2 is =0; --i){ string tmp = multi(num1, num2[i]... 阅读全文