摘要： Given a collection of integers that might contain duplicates, nums, return all possible subsets (the power set). Note: The solution set must not conta 阅读全文

摘要： Given a set of distinct integers, nums, return all possible subsets (the power set). Note: The solution set must not contain duplicate subsets. For ex 阅读全文

摘要： Given two integers n and k, return all possible combinations of k numbers out of 1 ... n. For example,If n = 4 and k = 2, a solution is: 从1，。。。，n中选出k个 阅读全文

摘要： Given an array of strings, group anagrams together. For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], Return: Note: All inputs will be i 阅读全文

摘要： You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Note:You have to rotate the image in-place, which 阅读全文

摘要： 题目要求 对于其基础题PermutationsI请参考我的另一篇博客这里添加的难度在于，排列组合的数字中可能存在重复。这就需要想方法，将结果集中重复的结果删去。而这里，我参考了另一名答题者的答案，在试图将数字添入结果集中时，就判断会不会产生重复的结果，从而使避免重复。 PermutationsI也可 阅读全文

摘要： 参考：https://www.cnblogs.com/TenosDoIt/p/3735309.html Given two numbers represented as strings, return multiplication of the numbers as a string. Note: 阅读全文

摘要： A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move either down or right at any p 阅读全文

摘要： Given an array of integers sorted in ascending order, find the starting and ending position of a given target value. Your algorithm's runtime complexi 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: 这题是列举所有情况，回溯。 每次都是从头开始遍 阅读全文