称号 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], ] 原题链接(点我) 解题思路 组合问题,老思路---递归加循环,这个是组合里面比較简单的. 代码实现 class Solutio…

LeetCode第38题 The count-and-say sequence is the sequence of integers with the first five terms as following: 1. 1 2. 11 3. 21 4. 1211 5. 111221 1 is read off as "one 1" or 11.11 is read off as "two 1s" or 21.21 is read off as "one…

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], ] 这道题让求1到n共n个数字里k个数的组合数的所有情况,还是要用深度优先搜索DFS来解,根据以往的经验,像这种要求出所有结果的集合,一般…

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], ] 原题链接:https://oj.leetcode.com/problems/combinations/ 题目:给定两个整数n和k,返…

import java.util.ArrayList; import java.util.Arrays; import java.util.List; /** * Source : https://oj.leetcode.com/problems/combinations/ * * * Given two integers n and k, return all possible combinations of k numbers out of 1 ... n. * * For example,…

原题地址:https://oj.leetcode.com/problems/combinations/ 题意:组合求解问题. 解题思路:这种求组合的问题,需要使用dfs来解决. 代码: class Solution: # @return a list of lists of integers def combine(self, n, k): def dfs(start, valuelist): if self.count == k: ret.append(valuelist); return f…

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], ] 方法1:把用queue实现bfs,改为用vector自己实现bfs,没有用额外的内存来存储中间值,但是时间上会Time Limite…

题目: Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. The same repeated number may be chosen from C unlimited number of times. Note: All numbers (including target) w…

一天一道LeetCode系列 (一)题目 The count-and-say sequence is the sequence of integers beginning as follows: 1, 11, 21, 1211, 111221, - 1 is read off as "one 1" or 11. 11 is read off as "two 1s" or 21. 21 is read off as "one 2, then one 1&qu…

38. Count and Say The count-and-say sequence is the sequence of integers beginning as follows: 1, 11, 21, 1211, 111221, ... 1 is read off as "one 1" or 11. 11 is read off as "two 1s" or 21. 21 is read off as "one 2, then one 1&quo…