题目大意:是有M个猪圈,N个顾客,顾客要买猪,神奇的是顾客有一些猪圈的钥匙而主人MIRKO却没有钥匙,多么神奇?顾客可以在打开的猪圈购买任意数量的猪,只要猪圈里有足够数量的猪.而且当顾客打开猪圈后mirko就可以在打开的猪圈之间任意调整猪的数量,(顾客走了之后猪圈要关闭).问mirko怎样做能使顾客买到最多的猪 思路如下:(也是查的,具体原理和原因明天更新) 1.取超级源点和超级汇点: 2.当猪圈被第一次打开时,在源点与当前顾客之间连接一条边,容量为该猪圈的猪的头数: 3.当某个猪圈 不是被第一…

PIGS Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 18345   Accepted: 8354 Description Mirko works on a pig farm that consists of M locked pig-houses and Mirko can't unlock any pighouse because he doesn't have the keys. Customers come t…

[题意] 有M个猪圈,每个猪圈里初始时有若干头猪.一开始所有猪圈都是关闭的.依 次来了N个顾客,每个顾客分别会打开指定的几个猪圈,从中买若干头猪.每 个顾客分别都有他能够买的数量的上限.每个顾客走后,他打开的那些猪圈中的 猪,都可以被任意地调换到其它开着的猪圈里,然后所有猪圈重新关上.问总共 最多能卖出多少头猪.(1 <= N <= 100, 1 <= M <= 1000) 非常好的一道网络流建模题!最大的收获就是: 在面对网络流问题时,如果一时想不出很好的构图方法,不如先构造一个…

题目链接:http://poj.org/problem?id=3159思路:题目意思很简单,都与给定的条件dist[b]-dist[a]<=c,求dist[n]-dist[1]的最大值,显然这是差分约束的经典题,条件可以转化为dist[b]<=dist[a]+c,于是a->b直接连边,边权值为c,从而题目转化为图上求1->n的最短路,看了一下数据,30000个点,150000条边,果断用Dijkstra+priority_queue,1300MS+险过,orz. #include&…

PIGS Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 20738   Accepted: 9481 Description Mirko works on a pig farm that consists of M locked pig-houses and Mirko can't unlock any pighouse because he doesn't have the keys. Customers come t…

PIGS Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 18727   Accepted: 8508 Description Mirko works on a pig farm that consists of M locked pig-houses and Mirko can't unlock any pighouse because he doesn't have the keys. Customers come t…

PIGS Time Limit: 1000ms Memory Limit: 10000KB This problem will be judged on PKU. 64-bit integer(整数) IO format: %lld      Java class name: Main   Mirko works on a pig farm that consists of M locked pig-houses and Mirko can't unlock any pighouse becau…

原题 题目大意 给你m个猪圈以及每个猪圈里原来有多少头猪,先后给你n个人,每个人能打开一些猪圈并且他们最多想买Ki头猪,在每一个人买完后能将打开的猪圈中的猪顺意分配在这次打开猪圈里,在下一个人来之前 已打开的猪圈被锁上. 解析 以每个买猪的作为点,并建立原点和汇点. 每个猪圈的第一个访客和原点连一条该猪圈中猪数量的边,每个猪圈的访客(除了以第一个)和上一个访问这个猪圈的人连一条inf的边,每个人向汇点连一条最多买的数量的边. #include<cstdio> #include<queue…

PIGS Description Mirko works on a pig farm that consists of M locked pig-houses and Mirko can't unlock any pighouse because he doesn't have the keys. Customers come to the farm one after another. Each of them has keys to some pig-houses and wants to…

题意: m n   //有m个猪圈,n个人卖猪. a1...am    //编号为i的猪圈里有ai头猪. b1 c1...cb1 d1   //第i个人有bi把钥匙,分别是ci猪圈的,其它猪圈里的猪都是锁着的   他最多买di头猪 . . . bn c1...cbn dn 注意的是假如某买主有第一和第二个猪圈的钥匙,那么他买完猪以后这两个猪圈的个数我们可以随意调整,调整完将猪圈锁上. 求:最多能卖多少猪 思路: 源点到每个猪圈建边,容量为这个猪圈的猪的数量,然后买主与他有钥匙的猪圈建边,容量in…