Teamwork Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=4494 Description Some locations in city A has been destroyed in the fierce battle. So the government decides to send some workers to repair these location…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2686 Yifenfei very like play a number game in the n*n Matrix. A positive integer number is put in each area of the Matrix.Every time yifenfei should to do is that choose a detour which frome the top left…

2014 多校的B题,由于我不怎么搞图论,当时碰到这个题目,我怎么想都没往网络流方面弄,不过网络流真的是个好东西,对于状态多变,无法用动规或者数据结构来很好表示的时候,非常有用 这个题目要求每个点一定要访问到,并且每次访问的是没访问过的点,跳跃的方向为向右或者向下. 建图的时候,分成二分图,从一个超级源点向x部分建cap为1 cost为0的点,对所以可到达的点从x到y建cap为1,cost根据题目算出来,不过要算负值,因为我们要求得实际是最大费用,最后对结果求相反数即可.所有y部分的点对超级汇点…

题目大意: 有一个最大是100 * 100 的网格图,上面有 s 个 房子和人,人每移动一个格子花费1的代价,求最小代价让所有的人都进入一个房子.每个房子只能进入一个人. 算法讨论: 注意是KM 和 MCMF算法,我写的是MCMF算法,一开始想的是连10000个点,但是不会连那些大众点之间的边,只会连超级点和普通点之间的边.后来觉得只要连房子点和 人点就可以了.连从人到房子的边,容量是1,花费是他们之间的曼哈顿距离,然后超级源点和超级汇点像上面那样连接,注意连点的时候把他们每个点都具体化一下,就…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1533 On a grid map there are n little men and n houses. In each unit time, every little man can move one unit step, either horizontally, or vertically, to an adjacent point. For each little man, you need…

Coding Contest Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 1751    Accepted Submission(s): 374 Problem Description A coding contest will be held in this university, in a huge playground. The…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3667 思路:由于花费的计算方法是a*x*x,因此必须拆边,使得最小费用流模板可用,即变成a*x的形式.具体的拆边方法为:第i次取这条路时费用为(2*i-1)*a (i<=5),每条边的容量为1.如果这条边通过的流量为x,那正好sigma(2*i-1)(1<<i<<x)==x^2.然后就是跑最小费用最大流了. #include<iostream> #include<…

Matrix Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2350    Accepted Submission(s): 1241 Problem Description Yifenfei very like play a number game in the n*n Matrix. A positive integer number…

Tour Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 2925    Accepted Submission(s): 1407 Problem Description In the kingdom of Henryy, there are N (2 <= N <= 200) cities, with M (M <= 30000…

Cyclic Tour Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/65535 K (Java/Others)Total Submission(s): 1197    Accepted Submission(s): 626 Problem Description There are N cities in our country, and M one-way roads connecting them. Now Li…