原题地址:https://oj.leetcode.com/problems/subsets-ii/ 题意: 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 duplicat…

题意: 给一个集合,有n个可能相同的元素,求出所有的子集(包括空集,但是不能重复). 思路: 看这个就差不多了.LEETCODE SUBSETS (DFS) class Solution { public: vector<vector<int>> subsets(vector<int>& nums) { sort(nums.begin(),nums.end()); DFS(,nums,tmp); ans.push_back(vector<int>()…

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:https://oj.leetcode.com/problems/permutations-ii/ 题意: 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].…

原题地址:https://oj.leetcode.com/problems/n-queens-ii/ 题意:和N-Queens这道题其实是一样的,只不过这次要求返回的时N皇后的解的个数的问题. 解题思路:上道题使用了递归回溯的解法,这道题我们可以使用非递归回溯来解决,因为如果使用递归回溯来解决,那么代码和上道题几乎一样.在非递归的编程中,比较有技巧性的是如何来进行回溯. 代码: class Solution: # @return an integer def totalNQueens(self,…

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: […

class Solution {//生成全部[不反复]的组合.生成组合仅仅要採用递归,由序列从前往后遍历就可以. 至于去重,依据分析相应的递归树可知.同一个父节点出来的两个分支不能一样(即不能与前一个元素一样,且前一个元素要与之在同层). public: int *b,n; vector<int>a; vector<vector<int> >ans; void dfs(int id,int len){ if(len>0){ vector<int>v(b…

求集合的所有子集问题 LeetCode: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:…