hdu 1534(差分约束+spfa求最长路)】的更多相关文章

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1534 思路:设s[i]表示工作i的开始时间,v[i]表示需要工作的时间,则完成时间为s[i]+v[i].于是可以列出下列不等式: FAS  a b :b开始之后a结束,s[a]+v[a]>=s[b]; FAF a b  :b结束之后a结束,s[a]+v[a]>=s[b]+v[b]; ASF a b  :b结束之后a开始,s[a]>=s[b]+v[b]; ASA a b  :b开始之后a开始,…
题目链接: POJ:http://poj.org/problem?id=1201 HDU:http://acm.hdu.edu.cn/showproblem.php? pid=1384 ZOJ:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=508 Description You are given n closed, integer intervals [ai, bi] and n integers c1, ..., cn.…
题意:有n个点,n-1条边的无向图,已知每个点书的售价,以及在边上行走的路费,问任选两个点作为起点和终点,能获得的最大利益是多少. 分析: 1.从某个结点出发,首先需要在该结点a花费price[a]买书,然后再在边上行走,到达目的地后,在目的地b获得price[b]. 2.因此可以建立两个虚拟结点, 虚拟结点1连向n个点,边权分别为-price[i],表示以i为起点,需花费price[i]买书. n个点连向虚拟结点2,边权分别为price[i],表示以i为终点,通过卖书可得price[i]. 3…
http://acm.hdu.edu.cn/showproblem.php?pid=1317 XYZZY Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 3514    Accepted Submission(s): 973 Problem Description It has recently been discovered how t…
http://poj.org/problem?id=1932 spfa求最长路,判断dist[n] > 0,需要注意的是有正环存在,如果有环存在,那么就要判断这个环上的某一点是否能够到达n点,如果能,就说明可以到达,否则,就说明不能. /************************************************************************* > File Name: poj1932.cpp > Author: syhjh > Created…
Instantaneous Transference Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 6177   Accepted: 1383 Description It was long ago when we played the game Red Alert. There is a magic function for the game objects which is called instantaneous…
题目地址:https://www.luogu.com.cn/problem/P3627 第一次寒假训练的结测题,思路本身不难,但对于我这个码力蒟蒻来说实现难度不小-考试时肛了将近两个半小时才刚肛出来.我也是吐了 题面 Siruseri 城中的道路都是单向的.不同的道路由路口连接.按照法律的规定, 在每个路口都设立了一个 Siruseri 银行的 ATM 取款机.令人奇怪的是,Siruseri 的酒吧也都设在路口,虽然并不是每个路口都设有酒吧. Banditji 计划实施 Siruseri 有史以…
Father Christmas flymouse Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 3007   Accepted: 1021 Description After retirement as contestant from WHU ACM Team, flymouse volunteered to do the odds and ends such as cleaning out the computer…
传送门: http://acm.hdu.edu.cn/showproblem.php?pid=1224 Free DIY Tour Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 8692    Accepted Submission(s): 2804 Problem Description Weiwei is a software en…
Schedule Problem Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 1715    Accepted Submission(s): 757Special Judge Problem Description A project can be divided into several parts. Each part shoul…