Subsets II 题解 原创文章,拒绝转载 题目来源:https://leetcode.com/problems/subsets-ii/description/ Description Given a collection of integers that might contain duplicates, nums, return all possible subsets (the power set). Note: The solution set must not contain du…

Subsets II Given a collection of integers that might contain duplicates, S, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If S = [1,2,2], a so…

Given a collection of integers that might contain duplicates, nums, return all possible subsets (the power set). Note: The solution set must not contain duplicate subsets. Example: Input: [1,2,2] Output: [ [2], [1], [1,2,2], [2,2], [1,2], [] ] 这个题目思路…

Given a collection of integers that might contain duplicates, nums, return all possible subsets (the power set). Note: The solution set must not contain duplicate subsets. Input: [1,2,2] Output: [ [2], [1], [1,2,2], [2,2], [1,2], [] ] 题意: 是的[leetcode…

Given a collection of integers that might contain duplicates, nums, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example, If nums = [1,2,2], a soluti…

Given a collection of integers that might contain duplicates, nums, return all possible subsets (the power set). Note: The solution set must not contain duplicate subsets. For example,If nums = [1,2,2], a solution is: [ [2], [1], [1,2,2], [2,2], [1,2…

http://oj.leetcode.com/problems/subsets/ 计算一个集合的子集,使用vector<vector<int> >,使用了进制的思想. #include<algorithm> #include<vector> #include<iostream> #include<cmath> using namespace std; class Solution { private: void myoutput(ve…

深度优先搜索算法(depth first search),是一个典型的图论算法.所遵循的搜索策略是尽可能“深”地去搜索一个图. 算法思想是: 对于新发现的顶点v,如果它有以点v为起点的未探测的边,则沿此边继续探测下去.当顶点v的所有边都已被探寻结束,则回溯到到达点v的先辈节点.以相同方法一直回溯到源节点为止.如果图中还有未被发现的顶点,则选择其中一个作为源顶点,重复以上的过程.最后的结果是一些不相交的深度优先树. leetCode中的应用: Given a collection of integ…

Given a collection of integers that might contain duplicates, nums, return all possible subsets. Note: The solution set must not contain duplicate subsets. For example,If nums = [1,2,2], a solution is: [ [2], [1], [1,2,2], [2,2], [1,2], [] ] 题目标签:Arr…

题目: Given a collection of integers that might contain duplicates, S, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If S = [1,2,2], a solution…

Given a collection of integers that might contain duplicates, S, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If S = [1,2,2], a solution is:…

Given a collection of integers that might contain duplicates, S, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If S = [1,2,2], a solution is:…

原题地址 跟Subsets(参见这篇文章)类似. 但因为有重复元素,所以要考虑去重问题. 什么情况下会出现重复呢?比如S = {5, 5, 5},如果要选1个5,一共有C(3,1)=3种选法,即100, 010, 001,这三种情况在集合的角度看是重复的情况.如果要选2个5,共有C(3,2)=3种选法,即011, 101, 110,这三种情况在集合的角度上看也是重复的. 本质在于,如果要在重复出现的数字当中选择若干个,则只能保留一种取法,其他的都是重复.即,这些重复数字对应的二进制位当中,只能保…

给定一个数组,返回所有的非重复的可能.例如给定 If S = [1,2,2], a solution is: [ [2], [1], [1,2,2], [2,2], [1,2], [] ] 其实这题类似的有Combination和Subsets.有兴趣的可以看看之前的解题方法.那大概是第70题左右,十天以前做的吧.记得当时用了回溯法.现在这个还是要用到回溯.只是加了判断有重复的子集怎么办. 在回溯的过称中,记录一种可能后就把最后一个pop掉,然后回溯上一个的时候判断是不是和之前判断过的相等了.用…

Given a collection of integers that might contain duplicates, nums, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example, If nums = [1,2,2], a soluti…

目录 题目链接 注意点 解法 小结 题目链接 Subsets II - LeetCode 注意点 有重复的数字 数组可能是无序的,要先排序 解法 解法一:递归,只需要在Subsets中递归写法的基础上多加一句if(find(ret.begin(),ret.end(),tmp) == ret.end()) ret.push_back(tmp);j即可,因为已经排序了,所以加进去的如果已经存在就说明是重复的. class Solution { public: typedef vector<int>…

1. Word Search Given a 2D board and a word, find if the word exists in the grid. The word can be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically neighboring. The same letter cel…

Leetcode之回溯法专题-90. 子集 II(Subsets II) 给定一个可能包含重复元素的整数数组 nums,返回该数组所有可能的子集(幂集). 说明:解集不能包含重复的子集. 示例: 输入: [1,2,2] 输出: [ [2], [1], [1,2,2], [2,2], [1,2], [] ] 分析:是78题的升级版,新增了一些限制条件,nums数组是会重复的,求子集. class Solution { List<List<Integer>> ans = new Arr…

1.  Subsets Given a set of distinct integers, S, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example, If S = [1,2,3], a solution is: [ [3], [1], […

Subsets II Given a collection of integers that might contain duplicates, S, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If S = [1,2,2], a so…

第一题是输入数组的数值不相同,第二题是输入数组的数值有相同的值,第二题在第一题的基础上需要过滤掉那些相同的数值. level代表的是需要进行选择的数值的位置. 78. Subsets 错误解法: class Solution { public: vector<vector<int>> subsets(vector<int>& nums) { vector<vector<int> > result; if(nums.empty()) ret…

Given a set of distinct integers, nums, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If nums = [1,2,3], a solution is: 求所有的子集合的问题,只不过这里的子集合里面…

Subsets II Given a collection of integers that might contain duplicates, nums, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If nums = [1,2,2]…

博客搬至blog.csgrandeur.com,cnblogs不再更新. 新的题解会更新在新博客:http://blog.csgrandeur.com/2014/01/15/LeetCode-OJ-Solution/ ———————————————————————————————————————— ———————————————————————————————————————— LeetCode OJ 题解 LeetCode OJ is a platform for preparing tech…

Valid Palindrome吐槽一下Leetcode上各种不定义标准的输入输出(只是面试时起码能够问一下输入输出格式...),此篇文章不是详细的题解,是自己刷LeetCode的一个笔记吧,尽管没有代码,可是略微难一点的都会标出主要思路,便于以后复习 PS:题目中有"水题"两字的都是一遍AC,没有标注的都说明了问题,顺序依照Leetcode上时间倒序排列,少量题目因为和之前的题目有相关性,因此将其放在一起,比方12题和13题,因此中间可能会"缺少"几道题目,缺少的…

题目: Given a collection of integers that might contain duplicates, nums, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If nums = [1,2,2], a sol…

一直没有系统地学习过算法,不过算法确实是需要系统学习的.大二上学期,在导师的建议下开始学习数据结构,零零散散的一学期,有了链表.栈.队列.树.图等的概念.又看了下那几个经典的算法——贪心算法.分治算法.动态规划以及回溯算法.不过,都是知其一不知其二的一知半解.到最后,发现学到了一堆的一知半解,在学校课程开这门课时,却又是不得不再学一遍.学一样东西,又不全心全意地主动去把它学好,到最后只是花费了时间,却没真真学到东西.所以,不求学识有多广,但求所学的都精. 一个偶然的机会,让我在网上找到了一本社区…

78. Subsets Given a set of distinct integers, nums, return all possible subsets. Note: The solution set must not contain duplicate subsets. For example, If nums = [,,], a solution is: [ [], [], [], [,,], [,], [,], [,], [] ] class Solution { public: v…

[leetcode]Word Ladder II @ Python 原题地址:http://oj.leetcode.com/problems/word-ladder-ii/ 参考文献:http://blog.csdn.net/doc_sgl/article/details/13341405   http://chaoren.is-programmer.com/ 题意:给定start单词,end单词,以及一个dict字典.要求找出start到end的所有最短路径,路径上的每个单词都要出现在dict…

一.Gray Code class Solution { public: vector<int> grayCode(int n) { vector<}; ) return result; return dfs(n); } vector<int> dfs(int n) { ) { vector<,}; return v; } vector<); int len=tmp.size(); ;i>=;i--) { tmp.push_back(tmp[i]+len);…