题目大意:在城市A的男孩想去城市B的女孩,不过他去城市B必须走最短路,并且走过的路不可以再走,问他最多能看这个女孩多少次.   分析:因为这个男孩直走最短路,所以我们必须求出来所有最短路径上的路,怎么判断一条路是否属于最短路经上的呢?其实比较容易的,只要先求出来从A到达所有点的最短路distA[x], 然后再求出来所有点到B的最短路distB[y](添加反边从B开始即可求出),如果x-y之间有一条路,那么只需要判断distA[x]+distB[y]+w(x,y) == distA[B] 是否成立…

题意 给你n个点,m条边,要求每条边只能走一次的S到T的最短路径的个数 题解 在我又WA又TLE还RE时,yyb大佬告诉我说要跑两遍SPFA,还说我写的一遍SPFA是错的,然而 啪啪打脸... 而且他的 比我跑得慢,2333 接下来讲一下方法 首先一遍SPFA(或dijkstra)从S跑一遍到所有点的最短路,重新建图时对于每对u, v 若 dis[u] + w[u][v] == dis[v] 则加入这条边,容量为1(还要加反边),最后跑最大流即可,最大流我用的是Dinic,然后注意手打队列,系统…

题意: 求有多少条最短路 解析: 正着求一遍最短路 得dis1 反着求一遍得 dis2   然后 遍历所有的边 如果  dis1[u] + dis2[v] + w == dis1[B], 则说明这是一条最短路边 建网络流的边 容量为1 代表这条边只能走一次 如果是无向边一次就好了, 就是挑出来所有符合条件的边 ------------------------------ 为什么我的代码的规范上边和下边不一样.....因为...emm...这是我半年前做的题..然而那时候只会EK 当然T了..会了…

HDU 3416 Marriage Match IV (最短路径,网络流,最大流) Description Do not sincere non-interference. Like that show, now starvae also take part in a show, but it take place between city A and B. Starvae is in city A and girls are in city B. Every time starvae can…

hdu 3416 Marriage Match IV Description Do not sincere non-interference. Like that show, now starvae also take part in a show, but it take place between city A and B. Starvae is in city A and girls are in city B. Every time starvae can get to city B a…

Marriage Match IV 题目链接: http://acm.hust.edu.cn/vjudge/contest/122685#problem/Q Description Do not sincere non-interference. Like that show, now starvae also take part in a show, but it take place between city A and B. Starvae is in city A and girls a…

Marriage Match IV http://acm.hdu.edu.cn/showproblem.php?pid=3416 Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 6081    Accepted Submission(s): 1766 Problem Description Do not sincere non-inter…

Marriage Match IV Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 6230    Accepted Submission(s): 1804 题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3416 Description: Do not sincere non-interfe…

题目链接:https://vjudge.net/problem/HDU-3416 Marriage Match IV Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4710    Accepted Submission(s): 1412 Problem Description Do not sincere non-interferenc…

Q - Marriage Match IV Do not sincere non-interference. Like that show, now starvae also take part in a show, but it take place between city A and B. Starvae is in city A and girls are in city B. Every time starvae can get to city B and make a data wi…