Given two integers n and k, return all possible combinations of k numbers out of 1 ... n. Example: Input: n = 4, k = 2 Output: [ [2,4], [3,4], [2,3], [1,2], [1,3], [1,4], ] class Solution { List<List<Integer>> res = new ArrayList<>(); pu…

https://leetcode.com/problems/combinations/ 沿用78题的思路 class Solution { public: void backTrack(vector<int> ans, vector<int> nums, vector<vector<int>>& res, int times,int k) { if(ans.size() == k) { res.push_back(ans); } else { for…

一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)题目 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: [ [2,4], [3,4], [2,3]…

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: [ [2,4], [3,4], [2,3], [1,2], [1,3], [1,4], ] 思路:遍历n以内的正整数,每个数有放入与不放入两种选择=>带回溯的递归 class Solution { public: vector…

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: [ [2,4], [3,4], [2,3], [1,2], [1,3], [1,4], ] Hide Tags Backtracking   这题是回溯题目,做好递归控制便可以了.   #include <iostream>…

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: [ [2,4], [3,4], [2,3], [1,2], [1,3], [1,4], ] 带回溯的递归.(带回溯没法用循环实现) class Solution { public List<List<Integer>&…

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/combinations/description/ 题目描述 Given two integers n and k, return all possible combinations of k numbers out of 1 - n. For…

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: [ [2,4], [3,4], [2,3], [1,2], [1,3], [1,4], ] class Solution(object): def combine(self, n, k): """ :ty…

题目: 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: [ [2,4], [3,4], [2,3], [1,2], [1,3], [1,4], ] Hide Tags Backtracking  链接:  http://leetcode.com/problems/combi…

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: [ [2,4], [3,4], [2,3], [1,2], [1,3], [1,4], ] 做了好几个这种题了,就是 backtrack problem, 1小时做出,但不容易,各种小毛病. 我的程序蠢蠢的建立了一个 vec…