题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=6178 题意:给出一棵有n个节点的树,现在需要你把k只猴子放在节点上,每个节点最多放一只猴子,且要求每只猴子必有一只另外的猴子通过一条边与它相连,问最少用多少条边能达到这个要求. 解法:利用贪心的思维,显然我们应该先选择性价比最高的,即一条边连接两个点的情况.计算出这样的边的条数ans,如果ans*2>=k,结果就是(k+1)/2,否则剩下来没有安排的猴子每一只需要多一条边,即结果为ans+k-2 *…

http://acm.hdu.edu.cn/showproblem.php?pid=6178 题意:现在有一n个顶点的树形图,还有k只猴子,每个顶点只能容纳一只猴子,而且每只猴子至少和另外一只猴子通过边相连,现在要删边,保留最少的边使得满足题意. 思路: 贪心的想一想,顶点两两匹配时一条边的贡献值就是两只猴子,那这不就是二分匹配吗.所以先求个二分匹配即可,然后如果此时还是不够的话,那么剩下的猴子每只猴子都需要一条边. 如果用二分匹配的算法可能不太行,虽然看别人用Hopcroft-Carp算法跑了…

http://acm.hdu.edu.cn/showproblem.php?pid=6178 [题意] 给定一棵有n个结点的树,现在有k个猴子分布在k个结点上,我们可以删去树上的一些边,使得k个猴子每个猴子都至少和其他一个猴子相连 问树上最少保留多少条边 [思路] 每个猴子要至少和一个猴子相连,考虑保留的边最少,那么最优的情况一定是一条边的两个顶点放两个猴子,这些边的顶点都不重合 我们现在要找到给定的树中最多有多少条这样的边,即最大二分匹配 O(n)的DFS,对于每个结点,优先与叶子结点形成一条…

There is a tree having N vertices. In the tree there are K monkeys (K <= N). A vertex can be occupied by at most one monkey. They want to remove some edges and leave minimum edges, but each monkey must be connected to at least one other monkey throug…

题意:给出一棵 N 个节点树,上面有 K 个猴子,然后竟可能删边,但是每一只猴子必须有直接相邻的猴子与之相邻.求最少剩下几条边. 分析:一条边可以用两只猴子站,这样的一条点对,越多越好,如果是ans个,ans*2>=k,那么只需要 (k+1)/2 条边. 否则,需要  ans + (k-ans*2) 条边. 现在问题就转为求这样的点对有多少,哈哈,有漏洞的DP都AC了,哈哈~~~~. 我发现标程思路也是这样,哈哈,都是bug程序!!! 唯一的解释就是 d[u][1] >= d[u][0] 感性…

J - Infinite monkey theorem Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Practice HDU 3689 Appoint description:  System Crawler  (2014-11-09) Description Could you imaging a monkey writing computer progra…

Infinite monkey theorem Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)http://acm.hdu.edu.cn/showproblem.php?pid=3689 Problem Description Could you imaging a monkey writing computer programs? Surely monkeys are sma…

题目链接:HDU - 1512 Once in a forest, there lived N aggressive monkeys. At the beginning, they each does things in its own way and none of them knows each other. But monkeys can't avoid quarrelling, and it only happens between two monkeys who does not kn…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=4414 CSUST:点击打开链接 Finding crosses Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 729    Accepted Submission(s): 411 Problem Description The Nazca L…

Saving HDU Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 7194    Accepted Submission(s): 3345 Problem Description 话说上回讲到海东集团面临内外交困,公司的元老也只剩下XHD夫妇二人了.显然,作为多年拼搏的商人,XHD不会坐以待毙的.  一天,当他正在苦思冥想解困良策的…