这道题细节真的非常多 首先能够想到a和b的最优策略一定是沿着a和b在树上的链走,走到某个点停止,然后再依次占据和这个点邻接的边 所以,解决这道题的过程例如以下: 预处理阶段: step 1:取随意一个点为根节点.找出父子关系而且对这个树进行dp.求出从某个节点出发往下所包括的全部边的权值总和  复杂度O(n) step 2:从tree dp 的结果中计算对于某个节点.从某条边出发所包括的边的综合.而且对其从大到小进行排序 复杂度O(n*logn) step 3:dfs求出这颗树的欧拉回路,以及每…

Bob intends to color the nodes of a tree with a pen. The tree consists of NN nodes. These nodes are numbered 1,2,...,N1,2,...,N. The root of the tree is node 11. The initial color of each node is white. Bob can use one unit energy to color one node i…

一棵树,结点树为n,根结点为r.每个结点都有一个权值ci,开始时间为0,每染色一个结点需要耗时1,每个结点的染色代价为ci*ti(ti为当前的时间),每个结点只有在父结点已经被染色的条件下才能被染色.求染完整棵树需要花费的最小代价. 找出当前最大子节点和其父节点合并成新的节点直到点集中只剩一个节点因为合并时将子节点的权值加在父节点上则 每次更新 答案加上当前子节点的权值乘上父节点的花费时间,这个很神奇 因为合并后,当对其父节点操作时也会重复加上子节点权值,即累加起来等同于每一个节点的最初权值乘上…

/* 十分巧妙的二分 题意选最少的点涂色 使得满足输入信息: 1 x的子树涂色数不少于y 2 x的子树外面涂色数不少于y 我们若是把2转化到子树内最多涂色多少 就可以维护这个最小和最大 如果我们二分出了答案 就可以完成转化 转化后也恰好可以判断二分是否合法 */ #include<cstdio> #include<cstring> #include<iostream> #define maxn 100010 using namespace std; int T,n,m,…

HDU.1556 Color the ball (线段树 区间更新 单点查询) 题意分析 注意一下pushdown 和 pushup 模板类的题还真不能自己套啊,手写一遍才行 代码总览 #include <bits/stdc++.h> #define nmax 200000 using namespace std; struct Tree{ int l,r,val; int lazy; int mid(){ return (l+r)>>1; } }; Tree tree[nmax&…

贪心....                    Color a Tree Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 6647   Accepted: 2249 Description Bob is very interested in the data structure of a tree. A tree is a directed graph in which a special node is single…

Color the ball Time Limit: 9000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 8984    Accepted Submission(s): 4594 Problem Description N个气球排成一排,从左到右依次编号为1,2,3....N.每次给定2个整数a b(a <= b),lele便为骑上他的“小飞鸽"牌电动车从气球…

Color the ball Time Limit: 9000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 7941    Accepted Submission(s): 4070 Problem Description N个气球排成一排,从左到右依次编号为1,2,3....N.每次给定2个整数a b(a <= b),lele便为骑上他的“小飞鸽"牌电动车从气球…

Color a Tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 828    Accepted Submission(s): 272 Problem DescriptionBob is very interested in the data structure of a tree. A tree is a directed gr…

Dylans loves tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 1444    Accepted Submission(s): 329 Problem Description Dylans is given a tree with N nodes. All nodes have a value A[i].Nodes…

题目链接: Hdu 5416 CRB and Tree 题目描述: 给一棵树有n个节点,树上的每条边都有一个权值.f(u,v)代表从u到v路径上所有边权的异或值,问满足f(u,v)==m的(u, v)有多少中情况(u, v有可能相同)? 解题思路: 由于xor的特殊性质.x^x=0,对于求f(u, v) == f(u, 1) ^ f(1, u). 又因为x^y == z可以推出x^z == y,对于f(u, 1) ^ f(1, v) == m可以转化为m ^ f(1, v) == f(u, 1)…

Hdu 5274 Dylans loves tree (树链剖分模板) 题目传送门 #include <queue> #include <cmath> #include <cstdio> #include <cstring> #include <cstdlib> #include <iostream> #include <algorithm> #include <vector> #define ll long…

题干 Bob is very interested in the data structure of a tree. A tree is a directed graph in which a special node is singled out, called the "root" of the tree, and there is a unique path from the root to each of the other nodes. Bob intends to colo…

Color a Tree 题目链接 好不可做?可以尝试一下DP贪心网络流.DP 似乎没法做,网络流也不太行,所以试一下贪心. 考虑全局中最大权值的那个点,如果它没父亲,那么一定会先选它:否则,选完它父亲就一定先选它.于是我们可以把它缩成一个点. 但是我们并不知道缩点后的权值是多少,这样就没法继续缩下去.我们考虑一对被缩点的父子 \(x,y\),以及全局中的另一个点 \(a\),什么时候会先选 \(a\),什么时候先选 \(x,y\).如果先选 \(x,y\),那么就有 \(x + 2y + 3a…

Bob intends to color the nodes of a tree with a pen. The tree consists of NN nodes. These nodes are numbered 1,2,...,N1,2,...,N. The root of the tree is node 11. The initial color of each node is white. Bob can use one unit energy to color one node i…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=6241 题意:给你一棵有 n 个结点的树,每个结点初始颜色都为白色,有 A 个条件:结点 x_i 的黑色结点数目不少于 y_i 个,同时有 B 个条件,除了结点 x_j 及其子树外至少有 y_j 个结点,求把最少要染成黑色结点的数目使得满足 A + B 个条件. 题解:参考自:https://blog.csdn.net/u013534123/article/details/78523559 #incl…

CRB and Tree Time Limit: 8000/4000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 2112    Accepted Submission(s): 635 Problem Description CRB has a tree, whose vertices are labeled by 1, 2, …, N. They are connected…

题意:给你n个球排成一行,初始都为黑色,现在给一些操作(L,R,color),给[L,R]区间内的求染上颜色color,'w'为白,'b'为黑.问最后最长的白色区间的起点和终点的位置. 解法:先离散化,为了防止离散后错误,不仅将L,R离散,还要加入L+1,L-1,R+1,R-1一起离散,这样就绝不会有问题了.然后建线段树,线段树维护四个值: 1.col  区间颜色  0 表示黑  1 表示白  -1表示无标记 2.maxi 区间内最大白区间的长度,由于白色用1表示,所以最大白区间的长度即为区间最…

http://acm.hdu.edu.cn/showproblem.php?pid=1199 Color the Ball Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 5135    Accepted Submission(s): 1262 Problem Description There are infinite balls i…

Big binary tree Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 597    Accepted Submission(s): 207 Problem Description You are given a complete binary tree with n nodes. The root node is numbere…

Dylans loves tree http://acm.hdu.edu.cn/showproblem.php?pid=5274 Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others) Problem Description Dylans is given a tree with N nodes. All nodes have a value A[i] .Nodes on tree…

Big binary tree Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 670    Accepted Submission(s): 235 Problem Description You are given a complete binary tree with n nodes. The root node is numbere…

Color the ball Time Limit: 9000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 5397    Accepted Submission(s): 2882 Problem Description N个气球排成一排,从左到右依次编号为1,2,3....N.每次给定2个整数a b(a <= b),lele便为骑上他的“小飞鸽"牌电动车从气球…

备忘. 差分数组: 区间更新查询有很多方法,线段树.树状数组等都可以.如果为离线查询,就可以考虑使用差分数组. 假设对于区间[l,r]的每个数都加1,我们用一个数组a来记录,a[l]+=1;a[r+1]-=1; 然后使用一个数组ans来记录数组a的前缀和,ans[i]=ans[i-1]+a[i];ans保存的就是所有更新操作完成后每个数对应的值. 原理很好理解,树状数组也有这种思想. 差分数组代码可比线段树短了相当多,记住这个还是很好的. Color the ball Time Limit: 9…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2489 Problem Description For a tree, which nodes and edges are all weighted, the ratio of it is calculated according to the following equation. Given a complete graph of n nodes with all nodes and edges…

Color the ball Time Limit: 9000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 22122    Accepted Submission(s): 10715 Problem Description N个气球排成一排,从左到右依次编号为1,2,3....N.每次给定2个整数a b(a <= b),lele便为骑上他的“小飞鸽"牌电动车从…

Color the ball Time Limit: 9000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 14711    Accepted Submission(s): 7354 Problem Description N个气球排成一排,从左到右依次编号为1,2,3....N.每次给定2个整数a b(a <= b),lele便为骑上他的“小飞鸽"牌电动车从气…

Color the ball 我真的该认真的复习一下以前没懂的知识了,今天看了一下线段树,以前只会用模板,现在看懂了之后,发现还有这么多巧妙的地方,好厉害啊 所以就应该尽量搞懂 弄明白每个知识点 [题目链接]Color the ball [题目类型]线段树区间更新 &题意: N个气球排成一排,从左到右依次编号为1,2,3....N.每次给定2个整数a b(a <= b),lele便为骑上他的"小飞鸽"牌电动车从气球a开始到气球b依次给每个气球涂一次颜色.但是N次以后lel…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1556 题目意思:有 n 个气球从左到右排成一排,编号依次为1,2,3,...,n.给出 n 对 a, b,表示编号为 a ~b 的气球被涂过一次色.n 次之后,问所有气球被上色的次数分别是多少. 典型的树状数组题!这种是:每次修改一个区间,问的是最后每个点被修改的次数.要注意update() 函数对 a 处理 的时候,向上修改的过程中把不必要的区间都加了一遍.例如对a = 2时,update修改了c…

Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 354    Accepted Submission(s): 100 Problem Description ZYB has a tree with N nodes,now he wants you to solve the numbers of nodes distanced no m…