虽然算法还没有理解透,但以及迫不及待地想要A道题了. 非常裸的最大流,试试lrj的模板练练手. #include <cstdio> #include <cstring> #include <algorithm> #include <vector> #include <queue> using namespace std; + ; ; struct Edge { int from, to, cap, flow; Edge(int u, int v,…

Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 69355   Accepted: 26873 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by…

http://poj.org/problem?id=1273 这道题很值得反思,弄了一下午,交上去先是一直编译错误,而在本地运行没有问题, 原因可能是oj的编译器版本老旧不支持这样的写法 G[from].push_back((edge){to,cap,G[to].size()}); G[to].push_back((edge){from,0,G[from].size() - 1}); 这两句交上去是不能通过的,不知道网上很多人这样子贴出代码是怎样通过的(‘白书’的模板有问题的) 如果是照着‘白书…

hdu 1532 题目大意: 就是由于下大雨的时候约翰的农场就会被雨水给淹没,无奈下约翰不得不修建水沟,而且是网络水沟,并且聪明的约翰还控制了水的流速,本题就是让你求出最大流速,无疑要运用到求最大流了.题中N为水沟数,M为水沟的顶点,接下来Si,Ei,Ci分别是水沟的起点,终点以及其容量.求源点1到终点M的最大流速.注意重边 Dinic算法的实现有以下几个步骤: 1:初始化容量网络和网络流 2:构造残留网络和层次网络,若汇点不在层次网络中则算法结束 输出最大流 3:在层次网络中用一次DFS进行增…

题意       有n个顾客,m个供应商,k种货物,给你顾客对于每种货物的要求个数,和供应商对于每种货物的现有量,以及供应每种货物的时候供应商和顾客之间的运输单价,问你满足所有顾客的前提下的最小运输费用是多少. 思路:       满足所有顾客的前提下的最小花费,很容易就想到了费用流,但是做这个题目有个小窍门,如果不想的话很可能把每个点拆成三个点,然后在去跑,但是这样感觉写着麻烦,AC肯定没问题,但是仔细想想,每种货物之间是没有任何关系的,那么我们何不直接每种货物都跑一遍费用流,这样写起来很简单…

题意:从1到n再到1,每条边只能走一次,求最短距离. 建图:每条边只能走一次就是流量是1,添加源点与1相连,容量为2,费用为0,n与汇点相连容量为2,费用为0: 求增广路用SPFA最短路求,, #include<stdio.h> #include<queue> #include<string.h> const int N=1100; const int inf=0x3fffffff; using namespace std; int cost[N],start,end,…

Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 59176   Accepted: 22723 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by…

题目链接:http://poj.org/problem?id=1273 Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes quite a long time to regrow. Thus, Farmer John has…

http://poj.org/problem?id=1273 Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 62708   Accepted: 24150 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means…

题目链接:http://poj.org/problem?id=1273 Time Limit: 1000MS Memory Limit: 10000K Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes…

http://poj.org/problem? id=1273 Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 55235   Accepted: 21104 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This mean…

题目链接:poj1273 Drainage Ditches 呜呜,今天自学网络流,看了EK算法,学的晕晕的,留个简单模板题来作纪念... #include<cstdio> #include<vector> #include<queue> #include<cstring> #include<set> #include<algorithm> #define CLR(a,b) memset((a),(b),sizeof((a))) usi…

点击打开链接 Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 49648   Accepted: 18829 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is cove…

Drainage DitchesHal Burch Time Limit 1000 ms Memory Limit 65536 kb description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes quite a…

Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 63924   Accepted: 24673 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by…

Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes quite a long time to regrow. Thus, Farmer John has built a set of drainage…

Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 53640   Accepted: 20448 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by…

一.Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes quite a long time to regrow. Thus, Farmer John has built a set of drainag…

链接 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes quite a long time to regrow. Thus, Farmer John has built a set of draina…

链接: http://poj.org/problem?id=1273 Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 63763   Accepted: 24613 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This m…

Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 67823   Accepted: 26209 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by…

POJ 1273给出M条边,N个点,求源点1到汇点N的最大流量. 本文主要就是附上dinic的模板,供以后参考. #include <iostream> #include <stdio.h> #include <algorithm> #include <queue> #include <string.h> /* POJ 1273 dinic算法模板 边是有向的,而且存在重边,且这里重边不是取MAX,而是累加和 */ using namespace…

Drainage Ditches 题目抽象:给你m条边u,v,c.   n个定点,源点1,汇点n.求最大流.  最好的入门题,各种算法都可以拿来练习 (1):  一般增广路算法  ford() #include <iostream> #include <cstdio> #include <cstring> #include <cmath> #include <algorithm> #include <string> #include…

题目链接: Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 67475   Accepted: 26075 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is cover…

Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 67387   Accepted: 26035 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by…

dinic版本 感觉dinic算法好帅,比Edmonds-Karp算法不知高到哪里去了 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes quite a long time to regrow. Th…

Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 74480   Accepted: 28953 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by…

Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 85250   Accepted: 33164 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by…

Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes quite a long time to regrow. Thus, Farmer John has built a set of drainage…

Drainage Ditches Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 63339   Accepted: 24434 Description Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by…