题意:给定上一个有向图,求 s - t 的最小割且边数最少. 析:设边的容量是w,边数为m,只要把每边打容量变成 w * (m+1) + 1,然后跑一个最大流,最大流%(m+1),就是答案. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <c…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=6214 题意:求边数最小的割. 解法: 建边的时候每条边权 w = w * (E + 1) + 1; 这样得到最大流 maxflow / (E + 1) ,最少割边数 maxflow % (E + 1) 道理很简单,如果原先两类割边都是最小割,那么求出的最大流相等 但边权变换后只有边数小的才是最小割了 乘(E+1)是为了保证边数叠加后依然是余数,不至于影响求最小割的结果 因为假设最小割=k,那么现在新…

hdu 6214 Smallest Minimum Cut[最大流] 题意:求最小割中最少的边数. 题解:对边权乘个比边大点的数比如300,再加1 ,最后,最大流对300取余就是边数啦.. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> #include<vector> #include<queue…

Smallest Minimum Cut Time Limit: 2000/2000 MS (Java/Others)    Memory Limit: 65535/32768 K (Java/Others)Total Submission(s): 1181    Accepted Submission(s): 473 Problem Description Consider a network G=(V,E) with source s and sink t. An s-t cut is a…

题目大意是给一张网络,网络可能存在不同边集的最小割,求出拥有最少边集的最小割,最少的边是多少条? 思路:题目很好理解,就是找一个边集最少的最小割,一个方法是在建图的时候把边的容量处理成C *(E+1 )+1,C是初始容量,E是边的个数,假设之前不做此操作处理求得最大流是maxf,处理之后跑dinic求出的最大流就是 maxf *(E+1)+ n , n就代表用了几条边,其中 n 必定是小于 E+1的,这样把处理之后的最大流模上(E+1)得到n,其中n就是最小割的边数,因为每用到一条边得到的最大流…

Problem Description Consider a network G=(V,E) with source s and sink t. An s-t cut is a partition of nodes set V into two parts such that s and t belong to different parts. The cut set is the subset of E with all edges connecting nodes in different…

Problem Description Consider a network G=(V,E) with source s and sink t . An s-t cut is a partition of nodes set V into two parts such that s and t belong to different parts. The cut set is the subset of E with all edges connecting nodes in different…

题目链接 ISAP写法 #include <bits/stdc++.h> using namespace std; typedef long long LL; namespace FastIO { const static int MX=1e6; ; char nc() { static char buf[MX],*p1=buf+MX,*pend=buf+MX; if(p1==pend) { p1=buf; pend=buf+fread(buf,,MX,stdin); if(pend==p1)…

Description Given an undirected graph, in which two vertices can be connected by multiple edges, what is the size of the minimum cut of the graph? i.e. how many edges must be removed at least to disconnect the graph into two subgraphs? Input Input co…

题目链接:http://poj.org/problem?id=2914 Minimum Cut Time Limit: 10000MS   Memory Limit: 65536K Total Submissions: 10117   Accepted: 4226 Case Time Limit: 5000MS Description Given an undirected graph, in which two vertices can be connected by multiple edg…