POJ 1087 A Plug for UNIX / HDU 1526 A Plug for UNIX / ZOJ 1157 A Plug for UNIX / UVA 753 A Plug for UNIX / UVAlive 5418 A Plug for UNIX / SCU 1671 A Plug for UNIX (网络流) Description You are in charge of setting up the press room for the inaugural meet…

POJ 1511 Invitation Cards / UVA 721 Invitation Cards / SPOJ Invitation / UVAlive Invitation Cards / SCU 1132 Invitation Cards / ZOJ 2008 Invitation Cards / HDU 1535 (图论,最短路径) Description In the age of television, not many people attend theater perfor…

最近开始刷网络流的题目了,先从紫书上的开始,这道题是P374上的,嘛,总之这道题最终还是参考了一下紫书. 中间是用了STL中map将字符串映射成编号,使用编号总比是用字符串简单的多. 超级源点S与各个设备对应插头类型连一条边,容量为1, 超级汇点T与各个插头连一条边,容量为1 然后如果有转换器,如果x->y,那么从点x连一条容量为正无穷的边到y (因为插头同类型的有无数个) 这样跑一发最大流即可,代码中间套用模板 #include<cstdio> #include<cstring&…

C - A Plug for UNIXTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=88038#problem/C Description You are in charge of setting up the press room for the inaugural meeting of the United Nations Internet…

题面 You are in charge of setting up the press room for the inaugural meeting of the United Nations Internet eXecutive (UNIX), which has an international mandate to make the free flow of information and ideas on the Internet as cumbersome and bureaucra…

链接: http://poj.org/problem?id=1087 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=82835#problem/C http://acm.hust.edu.cn/vjudge/contest/view.action?cid=88230#problem/J(密码:0817) n个插座,m个电器及其对应的插座,k个转化器,前一个插座可以转化为后一个插座,问最少有多少设备没有插座用,转换器数量不限最大流,源点…

You are in charge of setting up the press room for the inaugural meeting of the United Nations Internet eXecutive (UNIX), which has an international mandate to make the free flow of information and ideas on the Internet as cumbersome and bureaucratic…

题目链接:https://vjudge.net/problem/POJ-1087 题目:有n个插座,插座上只有一个插孔,有m个用电器,每个用电器都有插头,它们的插头可以一样, 有k个插孔转化器, a b 的意思就是  可以把 b类的插孔变成a类的插孔,那么a类对于的插头就可以用这个插孔充电了. 问:没插孔的用电器最少有几个. 思路:源点->插座->用电器->汇点. 因为插座之间可以相互转化,可能A,B,C,D都可以变成E类的插座,所以插座之间的流应该为INF,其他的边流都是1,起到限流的…

题意: 给n个插座,m个设备(肯定要插电了),k种转换头可无限次使用(注意是单向的),问有多少设备最终是不能够插上插座的? 分析: 看起来就是设备匹配插座,所以答案不超过m.这个题适合用网络流来解. 假设每种头对应着一个编号(可以用map实现转换string到int),主要在k种转换头的建边,他们之间的转换关系就是编号与编号之间的边,因为可以无限次使用,所以容量无穷.再添加源点和汇点就建完了,汇点连接每个插座,源点连接每个设备,每边容量为1.使用增广路算法就得出解了.注意要空一行. 很不愿意用结…

  A Plug for UNIX  You are in charge of setting up the press room for the inaugural meeting of the United Nations Internet eXecutive (UNIX), which has an international mandate to make the free flow of information and ideas on the Internet as cumberso…