连接:1018. Binary Apple Tree Time limit: 1.0 second Memory limit: 64 MB Let's imagine how apple tree looks in binary computer world. You're right, it looks just like a binary tree, i.e. any biparous branch splits up to exactly two new branches. We will…

题目链接: http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=17662 题目大意:树枝上间连接着一坨坨苹果(不要在意'坨'),给定留下m根树枝,问最后剩下的最多苹果是多少. 解题思路: 其实意思和Vijos 1180(选课)的意思差不多.只不过权在边而已. 首先建无向图dfs. for(f+1...j....cost) for(1....k...j-cost) 其中f为当前已经dfs子结点个数.之所以+1,是因为当前点也需要…

题目链接:http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=17662 思路:典型的树形dp,处理的时候类似于分组背包,dp[i][j]代表以i为根的树取j个分支获得的最大值. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<vector> using name…

本文出自   http://blog.csdn.net/shuangde800 --------------------------------------------------------------------------------- 题目链接:  url-1018 题意 给一棵边有权值的二叉树,节点编号为1-n,1是根节点.求砍掉一些边,只保留q条边,这q条边构成的子树    的根节点要求是1,问这颗子树的最大权值是多少? 思路 非常经典的一道树形dp题,根据我目前做过的题来看,有多道…

题目传送门 /* 题意:上司在,员工不在,反之不一定.每一个人有一个权值,问权值和最大多少. 树形DP:把上司和员工的关系看成根节点和子节点的关系,两者有状态转移方程: dp[rt][0] += max (dp[son][1], dp[son][0]); //上司不去 dp[rt][1] += dp[son][0]; //上司去,员工都不去 */ #include <cstdio> #include <cstring> #include <algorithm> #inc…

题目: 题目背景 URAL:http://acm.timus.ru/problem.aspx?space=1&num=1018 题目描述 有一棵苹果树,如果树枝有分叉,一定是分 2 叉(就是说没有只有 1 个儿子的结点,这棵树共有N 个结点(叶子点或者树枝分叉点),编号为1-N,树根编号一定是1. 我们用一根树枝两端连接的结点的编号来描述一根树枝的位置.下面是一颗有 4 个树枝的树:         2    5          \ /              3    4         …

切题ing!!!!! HDU  2196 Anniversary party 经典树形DP,以前写的太搓了,终于学会简单写法了.... #include <iostream> #include <cstdio> #include <cstring> #include <cstdlib> #include <cmath> #include <map> #include <queue> #include <set>…

Anniversary party Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 3862   Accepted: 2171 Description There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarchical structure…

Anniversary party Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 3863   Accepted: 2172 Description There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarchical structure…

A - 树形dp Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Description There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarchical structure…

Anniversary party Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 4310    Accepted Submission(s): 1976 Problem Description There is going to be a party to celebrate the 80-th Anniversary of the…

树形DP入门 有些时候,我们需要在树形结构上进行动态规划来求解最优解. 例如,给定一颗\(N\)个节点的树(通常是无根树,即有\(N-1\)条无向边),我们可以选择任意节点作为根节点从而定义出每一颗子树的深度,形成一个子问题重叠的结构,是符合动态规划前提的.在设计动态规划算法时,一般由节点由深到浅的顺序来作为\(DP\)的阶段.\(DP\)的状态表示中,数组的第一维通常表示子树根节点的编号.大多数时候,我们用递归的形式实现树形动态规划.先在它的每个子节点上递归求出最优解,再在返回时求解当前节点的…

Anniversary party Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 12770    Accepted Submission(s): 5142 Problem Description There is going to be a party to celebrate the 80-th Anniversary of the…

没有上司的舞会  时间限制: 1 s  空间限制: 128000 KB  题目等级 : 钻石 Diamond   题目描述 Description Ural大学有N个职员,编号为1~N.他们有从属关系,也就是说他们的关系就像一棵以校长为根的树,父结点就是子结点的直接上司.每个职员有一个快乐指数.现在有个周年庆宴会,要求与会职员的快乐指数最大.但是,没有职员愿和直接上司一起与会. 输入描述 Input Description 第一行一个整数N.(1<=N<=6000)接下来N行,第i+1行表示i…

题目链接:http://poj.org/problem?id=2342 Description There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarchical structure of employees. It means that the supervisor relation forms a tree…

题目传送门 没有上司的舞会 题目描述 Description Ural大学有N个职员,编号为1~N.他们有从属关系,也就是说他们的关系就像一棵以校长为根的树,父结点就是子结点的直接上司.每个职员有一个快乐指数.现在有个周年庆宴会,要求与会职员的快乐指数最大.但是,没有职员愿和直接上司一起与会. 输入描述 Input Description 第一行一个整数N.(1<=N<=6000)接下来N行,第i+1行表示i号职员的快乐指数Ri.(-128<=Ri<=127)接下来N-1行,每行输…

Anniversary party Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 10388   Accepted: 5943 Description There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarchical structur…

Anniversary party Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 3623    Accepted Submission(s): 1684 Problem Description There is going to be a party to celebrate the 80-th Anniversary of the…

传送门: http://acm.hdu.edu.cn/showproblem.php?pid=1520 Anniversary party Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 16376    Accepted Submission(s): 6241 Problem Description There is going to…

题目描述 Ural大学有N个职员,编号为1~N.他们有从属关系,也就是说他们的关系就像一棵以校长为根的树,父结点就是子结点的直接上司.每个职员有一个快乐指数.现在有个周年庆宴会,要求与会职员的快乐指数最大.但是,没有职员愿和直接上司一起与会. 输入 第一行一个整数N.(1<=N<=6000)接下来N行,第i+1行表示i号职员的快乐指数Ri.(-128<=Ri<=127)接下来N-1行,每行输入一对整数L,K.表示K是L的直接上司.最后一行输入0,0. 输出 输出最大的快乐指数. 样…

Anniversary party Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 15968    Accepted Submission(s): 6125 Problem Description There is going to be a party to celebrate the 80-th Anniversary of the…

There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarchical structure of employees. It means that the supervisor relation forms a tree rooted at the rector V. E. Tretyakov. In order…

1380 没有上司的舞会 时间限制: 1 s 空间限制: 128000 KB 题目等级 : 钻石 Diamond 题解 查看运行结果 回到问题 题目描述 Description Ural大学有N个职员,编号为1~N.他们有从属关系,也就是说他们的关系就像一棵以校长为根的树,父结点就是子结点的直接上司.每个职员有一个快乐指数.现在有个周年庆宴会,要求与会职员的快乐指数最大.但是,没有职员愿和直接上司一起与会. 输入描述 Input Description 第一行一个整数N.(1<=N<=6000…

传送门:http://poj.org/problem?id=2342 Anniversary party Time Limit: 1000MS Memory Limit: 65536K Description There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarchical structure of empl…

poj2342 Anniversary party (树形dp) Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9128   Accepted: 5250 Description There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarc…

Problem Description There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarchical structure of employees. It means that the supervisor relation forms a tree rooted at the rector V. E.…

Anniversary party Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 8667    Accepted Submission(s): 3748 Problem Description There is going to be a party to celebrate the 80-th Anniversary of the…

概念 应用 例题 最大独立子集 没有上司的晚会 题目描述 分析 树的重心 题目描述 分析 树的直径 概念 题目描述 分析 概念 给定一棵有N个节点的树(通常是无根树,也就是有N-1条无向边),我们可以任选一个节点为根节点,从而定义出每个节点的深度和每棵子树的根. 在树上设计动态规划算法时,一般就以节点从深到浅(子树从小到大)的顺序作为DP的"阶段".DP的状态表示中,第一维通常是节点编号(代表以该节点为根的子树).大多数时候,我们采用递归的方式实现树形动态规划.对于每个节点x,先递归在…

Network Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 4478   Accepted: 1292 Description Yixght is a manager of the company called SzqNetwork(SN). Now she's very worried because she has just received a bad news which denotes that DxtNet…

可以发现这道题的数据范围有些奇怪,为毛n辣么大,而k只有10 我们从树形dp的角度来考虑这个问题. 如果我们设f[x][k]表示与x距离为k的点的数量,那么我们可以O(1)回答一个询问 可是这样的话dp貌似就比较麻烦了. 我们考虑一般树形dp都是怎样的,一般的树形dp,都是因为子树上的f值可以无后效的转移到根节点上,并且子树的f值与父亲无关,如果我们按照上述定义,那么就会发现这需要两遍dfs来解决,并且细节不少. 但是两遍dfs我并不会QAQ 所以我们考虑转换一种定义,设f[x][k]表示在以x…