P3128 [USACO15DEC]最大流Max Flow 题目描述 Farmer John has installed a new system of N-1N−1 pipes to transport milk between the NN stalls in his barn (2 \leq N \leq 50,0002≤N≤50,000), conveniently numbered 1 \ldots N1…N. Each pipe connects a pair of stalls,…

P3128 [USACO15DEC]最大流Max Flow 题目描述 Farmer John has installed a new system of  pipes to transport milk between the  stalls in his barn (), conveniently numbered . Each pipe connects a pair of stalls, and all stalls are connected to each-other via path…

链接一下题目:luoguP3128 [USACO15DEC]最大流Max Flow(树上差分板子题) 如果没有学过树上差分,抠这里(其实很简单的,真的):树上差分总结 学了树上差分,这道题就极其显然了,不就是把每一条运输路线差分进去,那就是板子了啊. 树上差分还是很有用的,比较容易写,这种询问很少的题目去敲那么长(还容易出玄学错误)的树剖很浪费,用树上差分就很快了!(//...微笑...\\) 上一波代码: #include<iostream> #include<cstdlib>…

题目描述 Farmer John has installed a new system of  pipes to transport milk between the  stalls in his barn (), conveniently numbered . Each pipe connects a pair of stalls, and all stalls are connected to each-other via paths of pipes. FJ is pumping milk…

题目描述 Farmer John has installed a new system of  pipes to transport milk between the  stalls in his barn (), conveniently numbered . Each pipe connects a pair of stalls, and all stalls are connected to each-other via paths of pipes. FJ is pumping milk…

题目描述 Farmer John has installed a new system of N-1N−1 pipes to transport milk between the NN stalls in his barn (2 \leq N \leq 50,0002≤N≤50,000), conveniently numbered 1 \ldots N1…N. Each pipe connects a pair of stalls, and all stalls are connected t…

讲解: https://rpdreamer.blog.luogu.org/ci-fen-and-shu-shang-ci-fen #include <bits/stdc++.h> #define read read() #define up(i,l,r) for(register int i = (l);i <= (r);i++) #define down(i,l,r) for(register int i = (l);i >= (r);i--) #define traversal…

思路 这个题哪里有那么费脑筋 我们可以树链剖分嘛LCT昨天学的时候睡着了,不是太会 两遍dfs+一个5行的BIT 其实树链剖分学好了对倍增和LCT理解上都有好处 一条路径上的修改 由于一条剖出来的链是连续的,我们要选择数据结构维护 不过这里不用维护太多东西,只是区间+1 我们可以选择常数小,好写的树状数组(从50行的线段树变成5行的 BIT) 而且使得\(O(nlog_{2})\)的算法跑的并不慢 具体就是用差分思想,修改区间[L,R]时 $[1,R] +1 $ \([1,L-1] -1\)达到…

#\(\mathcal{\color{red}{Description}}\) \(Link\) \(FJ\)给他的牛棚的\(N(2≤N≤50,000)\)个隔间之间安装了\(N-1\)根管道,隔间编号从\(1\)到\(N\).所有隔间都被管道连通了. \(FJ\)有\(K(1≤K≤100,000)\)条运输牛奶的路线,第i条路线从隔间\(s_i\)运输到隔间\(t_i\).一条运输路线会给它的两个端点处的隔间以及中间途径的所有隔间带来一个单位的运输压力,你需要计算压力最大的隔间的压力是多少.…

FJ给他的牛棚的N(2≤N≤50,000)个隔间之间安装了N-1根管道,隔间编号从1到N.所有隔间都被管道连通了. FJ有K(1≤K≤100,000)条运输牛奶的路线,第i条路线从隔间si运输到隔间ti.一条运输路线会给它的两个端点处的隔间以及中间途径的所有隔间带来一个单位的运输压力,你需要计算压力最大的隔间的压力是多少. 思路: 比较基础的树剖题 对于每条线路 我们维护一个区间最大值的线段树 通过树剖实现每个加1的操作 最后读取总最大值就好 代码: // luogu-judger-enable…