Route Redundancy Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 625    Accepted Submission(s): 367 Problem Description A city is made up exclusively of one-way steets.each street in the city ha…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=3549 Flow Problem Time Limit: 5000/5000 MS (Java/Others)    Memory Limit: 65535/32768 K (Java/Others) Total Submission(s): 5111    Accepted Submission(s): 2385 Problem Description Network flow is a well-kn…

1.HDU 1532 最大流入门,n个n条边,求第1点到第m点的最大流.只用EK做了一下. #include<bits/stdc++.h> using namespace std; #pragma comment(linker, "/STACK:102400000,102400000") #define F(i,a,b) for (int i=a;i<b;i++) #define FF(i,a,b) for (int i=a;i<=b;i++) #define…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4240 A city is made up exclusively of one-way steets.each street in the city has a capacity,which is the minimum of the capcities of the streets along that route. The redundancy ratio from point A to poi…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4240 思路:题意真的有点难理解:在城市A->B之间通过所有路径一小时之内能通过最大的车辆(Maxflow)/所有边上通过最大车流量(cap)的那条叫做redundancy ratio.最小的redundancy ratio是前者最大的车流量的那一条(cap),问minimum redundancy ratio是多少. 其实就是跑一次最大流,每当找到一条增广路时,记录此时的cap,然后取最大的就行了.…

题意弄了半天: 给出一个有向图,带边权,src,dst. 求出src到dst的最大流,再求出从src到dst流量最大的路径的流量,求它们的比值. #include <cstdio> #include <cstring> #include <queue> #include <vector> #define oo 0x3f3f3f3f #define maxn 1010 using namespace std; struct Edge { int u, v, f…

大致题意:     给出一个又n个点,m条边组成的无向图.给出两个点s,t.对于图中的每个点,去掉这个点都需要一定的花费.求至少多少花费才能使得s和t之间不连通. 大致思路:     最基础的拆点最大流,把每个点拆作两个点 i 和 i' 连接i->i'费用为去掉这个点的花费,如果原图中有一条边a->b则连接a'->b.对这个图求出最大流即可. 画了个图,仔细看看似乎是这么回事 /* HDU 4289 G++ 62ms 1888K 最大流 SAP */ #include<stdio.…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=3549 模板题,白书上的代码... #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <queue> using namespace std; <<; ][],flow[][],n; int Edmonds_Karp(in…

http://acm.hdu.edu.cn/showproblem.php?pid=4240 题意:求最大流和流量最大的一条路径的流量的比值 题解:流量最大的路径的流量在dinic的dfs每次搜到终点的时候更新最大值 #include <cstdio> #include <cstring> #include <cstdlib> #include <iostream> #include <algorithm> using namespace std…

Route Redundancy Time Limit: 1000ms Memory Limit: 32768KB This problem will be judged on HDU. Original ID: 424064-bit integer IO format: %I64d      Java class name: Main   A city is made up exclusively of one-way steets.each street in the city has a…