Paint House There are a row of n houses, each house can be painted with one of the three colors: red, blue or green. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two adjacent houses…

[1]LeetCode 136 Single Number 题意:奇数个数,其中除了一个数只出现一次外,其他数都是成对出现,比如1,2,2,3,3...,求出该单个数. 解法:容易想到异或的性质,两个相同的数异或为0,那么把这串数从头到尾异或起来,最后的数就是要求的那个数. 代码如下: class Solution { public: int singleNumber(vector<int>& nums) { ; ;i<nums.size();i++) sum ^= nums[i…

leetcode - 40. Combination Sum II - Medium descrition Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. Each number in C may only be used once in the combinat…

LeetCode 137. Single Number II(只出现一次的数字 II)…

LeetCode:路径总和II[113] 题目描述 给定一个二叉树和一个目标和,找到所有从根节点到叶子节点路径总和等于给定目标和的路径. 说明: 叶子节点是指没有子节点的节点. 示例:给定如下二叉树,以及目标和 sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 返回: [ [5,4,11,2], [5,8,4,5] ] 题目分析 首先是一个深度搜索,来把所有根节点到叶子节点的路径找出来,然后各自判断是否等于目标值,等于目标值的路径加入结果集中.这…

LeetCode:组合总数II[40] 题目描述 给定一个数组 candidates 和一个目标数 target ,找出 candidates 中所有可以使数字和为 target 的组合. candidates 中的每个数字在每个组合中只能使用一次. 说明: 所有数字(包括目标数)都是正整数. 解集不能包含重复的组合. 示例 1: 输入: candidates = [10,1,2,7,6,1,5], target = 8, 所求解集为: [ [1, 7], [1, 2, 5], [2, 6],…

There are a row of n houses, each house can be painted with one of the k colors. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two adjacent houses have the same color. The cost of pai…

原题链接在这里:https://leetcode.com/problems/paint-house-ii/ 题目: There are a row of n houses, each house can be painted with one of the k colors. The cost of painting each house with a certain color is different. You have to paint all the houses such that n…

There is a fence with n posts, each post can be painted with one of the k colors. You have to paint all the posts such that no more than two adjacent fence posts have the same color. Return the total number of ways you can paint the fence. Note:n and…

There are a row of n houses, each house can be painted with one of the three colors: red, blue or green. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two adjacent houses have the sam…