二分图匹配: 分别按行和列把图展开.hungary二分图匹配. ... 例子: 4 4 *ooo o### **#* ooo* 按行展开. .. . *ooo o#oo oo#o ooo# **#o ooo* ooo* 再按列展开... 7 * 8 *ooooooo oooooooo oooooooo oooooooo *o*ooooo ooooooo* ooooooo* 匹配结果3 Battle ships Time Limit: 2000/1000 MS (Java/Others)    M…

Battle ships Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 1007    Accepted Submission(s): 353 Problem Description Dear contestant, now you are an excellent navy commander, who is responsible…

题目:pid=5093" target="_blank">hdoj 5093 Battle ships 题意:给你一个n*m的图,图中有冰山 '# ',浮冰 'o' 以及普通海 ' * ',如今要在海中布置尽可能多的炮弹.炮弹不能突波冰山,不能让炮弹互相攻击到.问最大能不知多少个? 分析:二分图的经典题目.关键在于怎么建图,图进行两次编号,按行编号,每一行中能攻击到的一块编号成相同的数,每一列相同.然后对行和列有编号的地方进行连边,求一次最大匹配就可以,我用最大流求的最…

Battle ships Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 1061    Accepted Submission(s): 377 Problem Description Dear contestant, now you are an excellent navy commander, who is responsible…

题意:一个m行n列的图由#.*.o三种符号组成,分别代表冰山.海域.浮冰,问最多可放的炮舰数(要求满足以下条件) 1.炮舰只可放在海域处 2.两个炮舰不能放在同一行或同一列(除非中间隔着一个或多个冰山) 分析: 1.如果单纯只考虑不能放在同一行同一列,那就是行号与列号的匹配,原理与UVALive 6811 Irrigation Line(二分图最小点覆盖--匈牙利算法)相同. 2.但现在隔着冰山可以放置炮舰,那假设某一行被冰山分隔成两部分,这一行的前半部分和后半部分可以看做是两行,再应用"行号&…

PIGS Time Limit: 1000MS   Memory Limit: 10000KB   64bit IO Format: %I64d & %I64u Submit Status 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…

Problem Description Thanks to a certain "green" resources company, there is a new profitable industry of oil skimming. There are large slicks of crude oil floating in the Gulf of Mexico just waiting to be scooped up by enterprising oil barons. O…

Muddy Fields Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 8881   Accepted: 3300 Description Rain has pummeled the cows' field, a rectangular grid of R rows and C columns (1 <= R <= 50, 1 <= C <= 50). While good for the grass, t…

比较经典的建图,详见进阶指南 2-sat一般要用到tarjan来求强连通分量 /*2-sat要加的是具有强制关系的边*/ #include<iostream> #include<cstring> #include<cstdio> using namespace std; #define N 2005 #define M 2000005 ]; int n,m,head[N],tot; void init(){ memset(head,-,sizeof head); } v…

题意:       有一个人,他有m个猪圈,每个猪圈里都有一定数量的猪,但是他没有钥匙,然后依次来了n个顾客,每个顾客都有一些钥匙,还有他要卖猪的数量,每个顾客来的时候主人用顾客的钥匙打开相应的门,可以调整猪的数量,然后卖给一些猪给这个顾客(卖多少自己决定),顾客走之后所有的们就都锁上了,问主人最多能买多少头猪. 思路:       经典的建图,这已经是我第三次做这个题目了,大一,大二,大三每年做流的时候都会想到它,然后回来做一次,没办法,感觉比较经典,虽然现在做着直接1A没有第一次做的时候千辛…