思路: 看了好久才看懂题意,文中给了n个点,有m个集合,每个集合有s个点,集合内的每两个点之间有一个权值为t的边,现在有两个人,要从1号点,和n号点,走到同一个顶点,问最少花费以及花费最少的点. 那就直接跑两遍最短路,然后枚举每一点,取最短路最大值最小的点. 然而这么浅显的做法却MLE啦,真是用心险恶的出题人呀. 其实仔细想一想就知道了,题目的要求是,每个集合里面,都是一个完全图,如果只有一个集合,那么2e5个点,边的条数就是4e10条,爆内存简直是必然的.所以需要在建图的时候优化,或者是换一种…

Meeting Time Limit: 12000/6000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others) Total Submission(s): 1358    Accepted Submission(s): 435 Problem Description Bessie and her friend Elsie decide to have a meeting. However, after Farmer Jo…

Meeting Time Limit: 12000/6000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 3361    Accepted Submission(s): 1073 Problem Description Bessie and her friend Elsie decide to have a meeting. However, after Farmer Jo…

今天旁观了Angry_Newbie的模拟区域赛(2015shenyang) 倒着看最先看的M题,很明显的最短路问题,在我看懂的时候他们已经开始敲B了. 后来听说D过了很多人.. D题一看是个博弈,给了很多组样例,找找规律懵一懵就ac了.然后我就滚粗了... 而他们也早就A了D,很快他们又A了B... 后来就全程看着罗大神敲无限TLE的M.感觉算法肯定没错,但是想不到哪里还可以优化. 后来我滚了之后听说他们也成功AC了M. 下来仔细想想M也并不是难题,如果平时做的话,肯定不会卡那么久的... A…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5521 题意:有1-n共n个点,给出m个块(完全图),并知道块内各点之间互相到达花费时间均为ti.已知两人分别在点1和点n,求在哪些点相遇能使得花费时间最短.题解:显然先想到从点1和点n分别求最短路,然后枚举点找出哪些点是相遇花费时间最少的.但是这题边太多了,假设一个完全图里有x个点,那边就有x*(x-1)/2条了,必须化简其边.一个可行的办法是给每个完全图增加两个点,分别为入点和出点,入点向其中的点…

题意:有N个点,两个人,其中一个人住在点1,另一个人住在点n,有M个点集,集合内的数表示任意两点的距离为dis ,现在问,如果两个人要见面, 需要最短距离是多少,有哪几个点能被当成见面点. 析:分别对1和n进行最短路操作,这个题最让人别扭的就是边太多,如果你直接全部都存下来,那么一定会MLE,所以一定要优化边.所以我们要把每一行的边都记下来, 而不是两两都记下,然后把每一行的编号记下来,最后要查询时,就行编号去定位到哪一行,这样就不会超内存.这里会了,其他的就很简单了. 代码如下: #pragm…

2015 ACM / ICPC 沈阳站现场赛 M题 最短路 设置N+M个节点,前N个节点是Block,后M个节点是Set,每一组Set中的点向该Set连边,从1和n开始分别求最短路.注意爆int. #include<cstdio> #include<cstring> #include<cmath> #include<vector> #include<queue> #include<algorithm> using namespace…

http://acm.hdu.edu.cn/showproblem.php?pid=5521 Meeting Problem Description   Bessie and her friend Elsie decide to have a meeting. However, after Farmer John decorated hisfences they were separated into different blocks. John's farm are divided into …

Meeting Time Limit: 12000/6000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 1656    Accepted Submission(s): 515 Problem Description Bessie and her friend Elsie decide to have a meeting. However, after Farmer Joh…

Problem Description Bessie and her friend Elsie decide to have a meeting. However, after Farmer John decorated hisfences they were separated into different blocks. John's farm are divided into n blocks labelled from 1 to n.Bessie lives in the first b…