Andryusha goes through a park each day. The squares and paths between them look boring to Andryusha, so he decided to decorate them. The park consists of n squares connected with (n - 1) bidirectional paths in such a way that any square is reachable…

http://codeforces.com/contest/782/problem/C 题意:给一棵树染最少的颜色,使得相邻距离为2的点都是不同的颜色,问最少是多少种颜色并输出每个点的颜色. 思路:比赛的时候没想到是找度最大的一个点并+1就是总颜色数,一直想怎么构造. 最后的总颜色数是度最大的一个点的度数+1.因为我们选的这个点到儿子的距离为1,因此其某一个儿子到另一个儿子的距离为2,就是这些儿子都要染成不同的颜色,+1是因为自己本身也要是不同的颜色. 然后确定了总颜色数,就可以DFS染色了.…

前言 完了,完了,咕值要没了,赶紧写题解QAQ. 题意简述 给相邻的三个节点颜色不能相同的树染色所需的最小颜色数. 题解 这道题目很显然可以用深搜. 考虑题目的限制,如果当前搜索到的点为u, 显然u的父亲节点,u本身和u的所有儿子不能同色(因为兄弟之间相差为2). 由于DFS解题,所以搜索到u时,u本身和u的父亲肯定已经有颜色了,那么现在要结局的使u的所有儿子的颜色,那么根据贪心的思想对于每个u的儿子,颜色能往小取就往小取,在选取颜色的时候应当注意,选取的颜色不能与u和u的父亲节点的颜色相同.…

C. Andryusha and Colored Balloons time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Andryusha goes through a park each day. The squares and paths between them look boring to Andryusha, so he…

C. Andryusha and Colored Balloons time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Andryusha goes through a park each day. The squares and paths between them look boring to Andryusha, so he…

C. Andryusha and Colored Balloons time limit per test:2 seconds memory limit per test:256 megabytes input:standard input output:standard output Andryusha goes through a park each day. The squares and paths between them look boring to Andryusha, so he…

地址:http://codeforces.com/contest/782/problem/C 题目: C. Andryusha and Colored Balloons time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Andryusha goes through a park each day. The squares and…

本文版权归ljh2000和博客园共有,欢迎转载,但须保留此声明,并给出原文链接,谢谢合作. 本文作者:ljh2000 作者博客:http://www.cnblogs.com/ljh2000-jump/转载请注明出处,侵权必究,保留最终解释权! 题目链接:codeforces781A Andryusha and Colored Balloons 正解:构造+结论 解题报告: 考虑答案显然是$max(度数)+1$,这个似乎很好想,对于每个点我需要保证与之相邻的所有点颜色互不相同且与自己不同,那么需要…

C - Andryusha and Colored Balloons 思路: 水题: 代码: #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> using namespace std; #define maxn 200005 ],V[maxn<<],dis[maxn],ans; void dfs(int now,int fa) { ; for…

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>()…