Permutations Given a collection of 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], and [3,2,1]. 解法一:递归 class Solution { public: vector<vector<int> > pe…

作者: 负雪明烛 id: fuxuemingzhu 个人博客:http://fuxuemingzhu.cn/ 目录 题目描述 解题方法 方法一:库函数 方法二:递归 方法三:回溯法 日期 题目地址:https://leetcode.com/problems/permutations/description/ 题目描述 Given a collection of distinct numbers, return all possible permutations. For example, [1,…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 方法一:递归 方法二:回溯法 日期 题目地址:https://leetcode.com/problems/permutations-ii/description/ 题目描述 Given a collection of numbers that might contain duplicates, return all possible unique p…

一天一道LeetCode系列 (一)题目 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], and [3,2,1]. (二)解题 求全排列数.具体思路可以参考[一天一道LeetCode]#31. Next…

Permutations II 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], and [2,1,1]. 首先分析一下与Permutations有何差异. 记当前位置为start,当前排列数…

题目: 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] ] 题解: Solution 1 (TLE) class Solution { public: void dfs…

题目: 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] ] 题解: 之前解过Next Permutation,故这个题可以重复调用nextPermutation函数产生全排列 Solu…

4Sum Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target. Note: Elements in a quadruplet (a,b,c,d) must be in non-descending o…

Anagrams Given an array of strings, return all groups of strings that are anagrams. Note: All inputs will be in lower-case. 首先解释一下什么是anagrams:在不考虑顺序的情况下,包含相同字母的字符串组成anagrams 例如: 1.{"eat","ate","tea","coffee"}的anagra…

Triangle Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below. For example, given the following triangle [ [], [,4], [6,,7], [4,,8,3] ] The minimum path sum from top to bottom is …