最大流算法,解决的是从一个起点到一个终点,通过任何条路径能够得到的最大流量. 有个Edmond-Karp算法: 1. BFS找到一条增广路径:算出这条路径的最小流量(所有边的最小值)increase: 2. 然后更新路径上的权重(流量),正向边加上increase,反向边减去increase; 3. 重复1,直到没有增广路径: 可以证明的是在使用最短路增广时增广过程不超过V*E次,每次BFS的时间都是O(E),所以Edmonds-Karp的时间复杂度就是O(V*E^2). 图的BFS和DFS的时…

First problem to learn Max Flow. Ford-Fulkerson is a group of algorithms - Dinic is one of it.It is an iterative process: we use BFS to check augament-ability, and use DFS to augment it. Here is the code with my comments from its tutorial #include <c…

问题描述 给定g个group,n个id,n<=g.我们将为每个group分配一个id(各个group的id不同).但是每个group分配id需要付出不同的代价cost,需要求解最优的id分配方案,使得整体cost之和最小. 例子 例如以下4个group,三个id,value矩阵A: value id1 id2 id3 H1 4 3 0 H2 1 0 0 H3 2 0 2 H4 3 1 0 id_i分配给H_j的代价\(changing cost[i, j]=\sum(A[j,:])-A[j,i]…

[Luogu 3128] USACO15DEC Max Flow 最近跟 LCA 干上了- 树剖好啊,我再也不想写倍增了. 以及似乎成功转成了空格选手 qwq. 对于每两个点 S and T,求一下 LCA 顺便树上差分,最后求差分数组的前缀和并找出最大值输出就行了. (PS:最近考前训练不开 C++11,所以如果看见我写了奇怪的 define 请自动无视QAQ!) #include <algorithm> #include <cstdio> #define nullptr NUL…

4390: [Usaco2015 dec]Max Flow Time Limit: 10 Sec  Memory Limit: 128 MBSubmit: 177  Solved: 113[Submit][Status][Discuss] Description Farmer John has installed a new system of N−1 pipes to transport milk between the N stalls in his barn (2≤N≤50,000), c…

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…

Max Flow 题目描述 Farmer John has installed a new system of N−1 pipes to transport milk between the N stalls in his barn (2≤N≤50,000), conveniently numbered 1…N. Each pipe connects a pair of stalls, and all stalls are connected to each-other via paths of…

[Usaco2015 dec]Max Flow Time Limit: 10 Sec  Memory Limit: 128 MBSubmit: 353  Solved: 236[Submit][Status][Discuss] Description Farmer John has installed a new system of N−1 pipes to transport milk between the N stalls in his barn (2≤N≤50,000), conveni…

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,…

BZOJ4390: [Usaco2015 dec]Max Flow Description Farmer John has installed a new system of N−1 pipes to transport milk between the N stalls in his barn (2≤N≤50,000), conveniently numbered 1…N. Each pipe connects a pair of stalls, and all stalls are conn…