You, a part-time dining service worker in your college’s dining hall, are now confused with a new problem: serve as many people as possible.  The issue comes up as people in your college are more and more difficult to serve with meal: They eat only s…

HDU 4292 Food (网络流,最大流) Description You, a part-time dining service worker in your college's dining hall, are now confused with a new problem: serve as many people as possible. The issue comes up as people in your college are more and more difficult…

ACM Computer Factory Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 10940   Accepted: 4098   Special Judge Description As you know, all the computers used for ACM contests must be identical, so the participants compete on equal terms. T…

http://acm.hdu.edu.cn/showproblem.php?pid=4292 给一些人想要的食物和饮料,和你拥有的数量,问最多多少人可以同时获得一份食物和一份饮料 写的时候一共用了2种拆点建图的方法... 1. 起点连接饮料和食物,容量为拥有的数量 每个人被拆成三个点,$a,b,c$  $a$被想要的食物连接,$b$被想要的饮料连接,$c$被$a,b$连接,容量均为1 然后$c$点连接汇点,容量为2,最后遍历所有静态链表节点,对于所有指向汇点的边,如果剩余容量为0,则答案++ 然…

/** 题目:UVA1658 Admiral 链接:https://vjudge.net/problem/UVA-1658 题意:lrj入门经典P375 求从s到t的两条不相交(除了s和t外,没有公共点)的路径,使得权值和最小. 思路:拆点法. 除了s,t外.把其他点都拆成两个. 例如点A,拆成A和A'.A指向A'连一条容量为1,花费为0的边. 原来指向A的,仍然指向A点. 原来A指向其他点的,由A'指向它们. 最小费用最大流求流量为2时候的最小费用即可. */ #include<iostrea…

题意:N个人,F种食物,D种饮料,给定每种食物和饮料的量.每个人有自己喜欢的食物和饮料,如果得到自己喜欢的食物和饮料才能得到满足.求最大满足的人数. 分析:如果只是简单地N个人选择F种食物的话可以用二分图匹配来完成,但是该题种一个人要选择两样东西. 采取以下操作建图: 增加源点和汇点,源点与F个食物相连,每条弧流量为第i种食物的数量:D个食物与汇点相连,每条弧流量为其数量. 所以将N个人拆成两个点,对应两点之间连一条边,流量为1. 然后跑出最大流就是答案. #include<bits/stdc+…

http://acm.hdu.edu.cn/showproblem.php?pid=4292 题意:和奶牛一题差不多,只不过每种食物可以有多种. 思路:因为食物多种,所以源点和汇点的容量要改下.还有Dinic又TLE了,用ISAP过. #include <cstdio> #include <algorithm> #include <iostream> #include <cstring> #include <string> #include &l…

Golden Eggs Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 304    Accepted Submission(s): 172 Problem Description There is a grid with N rows and M columns. In each cell you can choose to put a…

(点击此处查看原题) 题目分析 题意:某个餐馆出售f种食物,d种饮料,其中,第i种食物有fi份,第i种饮料有di份:此时有n个人来餐馆吃饭,这n个人必须有一份食物和一份饮料才会留下来吃饭,否则,他将离去,而且每个人只吃某几种食物和饮料,如果某个人留下来,那么必须提供一份他吃的食物和一份他吃饮料,问在这种情况下,最多可以招待多少人. 思路:这类的题目我总结为:最大流受到两个互不影响的物体的影响,这类题目为最大流题目,建边如下: 1)由源点向每一种食物i代表的结点建一条容量为fi的边 2)将每个顾客…

链接: http://acm.hdu.edu.cn/showproblem.php?pid=4292 Food Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4060    Accepted Submission(s): 1359 Problem Description You, a part-time dining service w…