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…

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…

一.题目说明 题目78. Subsets,给一列整数,求所有可能的子集.题目难度是Medium! 二.我的解答 这个题目,前面做过一个类似的,相当于求闭包: 刷题22. Generate Parentheses 算了,用最简单的回溯法吧: class Solution{ public: void dfs(vector<int>& nums,int start){ r.push_back(path); for(int i=start;i<len;i++){ path.push_ba…

本题还是基本的回溯法.就是回溯函数的参数选择上要花点心思! class Solution { public: void backTrack(vector<int> ans, vector<int> nums, vector<vector<int>>& res, int bgi) { for(int i = bgi; i<nums.size();i++) { ans.push_back(nums[i]); res.push_back(ans);…

  Given a set of distinct integers, nums, return all possible subsets (the power set). Note: The solution set must not contain duplicate subsets. Example: Input: nums = [1,2,3] Output: [ [3],   [1],   [2],   [1,2,3],   [1,3],   [2,3],   [1,2],   [] ]…

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: [ [3], [1], [2], [1,2…

这个回溯感觉掌握的有些熟练了. 两种方式,递归和循环. 感觉就是套框架了. /** * Return an array of arrays of size *returnSize. * The sizes of the arrays are returned as *columnSizes array. * Note: Both returned array and *columnSizes array must be malloced, assume caller calls free().…

题目链接:https://leetcode.com/problems/subsets/#/description   给出一个数组,数组中的元素各不相同,找到该集合的所有子集(包括空集和本身) 举例说明: int []nums={1,2,3}  返回结果如下: [ [3], [1], [2], [1,2,3], [1,3], [2,3], [1,2], [] ] 使用回溯法解决上述问题.   相当于对一棵树的深度遍历操作.    上述的输出结果还是有些规律的,也就是按照子集的元素个数来进行分解,…

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: [ [3], [1], [2], [1,2,…

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], [2], [1,2,3], [1…