hdu1217 Arbitrage Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 4123    Accepted Submission(s): 1878 Problem Description Arbitrage is the use of discrepancies in currency exchange rates to tr…

链接: http://acm.hdu.edu.cn/showproblem.php?pid=1317 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=29015#problem/F XYZZY Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 1701    Accepted S…

Several currency exchange points are working in our city. Let us suppose that each point specializes in two particular currencies and performs exchange operations only with these currencies. There can be several points specializing in the same pair o…

传送门:点击打开链接 题目大意:一个城市有n种货币,m个货币交换点,你有v的钱,每个交换点只能交换两种货币,(A换B或者B换A),每一次交换都有独特的汇率和手续费,问你存不存在一种换法使原来的钱更多. 思路:一开始以为一个地方只能用一次,感觉好像有点难,后来发现自己读错题了,其实只要判断给你的这幅图存不存在正环就可以了,用dis[]表示某种货币的数量,然后bellman判断正环就可以了.(题目里强调结尾一定要原来的货币,但其实这是废话,因为是以原来的货币为起点的,所以你换出去了一定换的回来),正…

//spfa 判断正环 #include<iostream> #include<queue> #include<cstring> using namespace std; const int N=1e4; const int INF=2e9; int h[N],to[N],ne[N],idx; double r[N],c[N]; int n, m,X; double V; void add(int u,int v,double r1,double c1) { to[id…

XYZZY Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4421    Accepted Submission(s): 1252 Problem Description It has recently been discovered how to run open-source software on the Y-Crate gami…

XYZZY Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 5304    Accepted Submission(s): 1510 Problem Description It has recently been discovered how to run open-source software on the Y-Crate gam…

http://poj.org/problem?id=3621 Sightseeing Cows Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7649   Accepted: 2567 Description Farmer John has decided to reward his cows for their hard work by taking them on a tour of the big city! Th…

Currency Exchange POJ - 1860 题意: 有许多货币兑换点,每个兑换点仅支持两种货币的兑换,兑换有相应的汇率和手续费.你有s这个货币 V 个,问是否能通过合理地兑换货币,使得你手中的货币折合成s后是有增加的. 思路: 这道题在建立每种货币的兑换关系后,找到图中的正环即可,因为你沿着正环跑就可以增加价值.这里可以用类似Bellman_Ford判断负环的方法. #include <algorithm> #include <iterator> #include &…

题意:给出n个房间,初始在房间1有100的能量值,每次进入一个房间,能量值可能增加也可能减小,(是点权,不是边权),问能否到达终点的时候能量值还为正 这题自己写的时候wa--wa-- 后来看了题解,还是wa---wa--- 题解很详细http://blog.csdn.net/freezhanacmore/article/details/9937327 记录下自己犯的错误吧 首先是floyd函数初始化的时候,直接写在了函数里面,这样是不对的,因为输入值在前,调用函数在后,这样就相当于将之前输入的可…