Arbitrage Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 16652   Accepted: 7004 Description Arbitrage is the use of discrepancies in currency exchange rates to transform one unit of a currency into more than one unit of the same currenc…

Arbitrage Problem Description Arbitrage is the use of discrepancies in currency exchange rates to transform one unit of a currency into more than one unit of the same currency. For example, suppose that 1 US Dollar buys 0.5 British pound, 1 British p…

和POJ1860差不多,就是用bellmanford判读是否存在正环,注意的是同种货币之间也可以交换,就是说:A货币换A货币汇率是2的情况也是存在的. #include<stdio.h> #include<string.h> #include<cstring> #include<string> #include<math.h> #include<queue> #include<algorithm> #include<…

链接: http://poj.org/problem?id=2240 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=22010#problem/F Arbitrage Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 13067   Accepted: 5493 Description Arbitrage is the use of discrepancies i…

题意: 给出一些货币和货币之间的兑换比率,问是否可以使某种货币经过一些列兑换之后,货币值增加. 举例说就是1美元经过一些兑换之后,超过1美元.可以输出Yes,否则输出No. 分析: 首先我们要把货币之间的关系转化成一张图.转化时,用STL里面的map很方便. 为每种货币分配一个序列号,一个序列号代表了一个图中间的NODE,而node之间的edge用汇率表示. 一开始用Dijkstra算法做,死活AC不了,网友给的理由是: 由于Dijkstra算法不能处理带有负权值的最短路,但此题中,两种货币之间…

题目:http://poj.org/problem?id=2240 题意:给定n个货币名称,给m个货币之间的汇率,求会不会增加 和1860差不多,求有没有正环 刚开始没对,不知道为什么用 double往结构体里传值的时候 会去掉小数点后的 数 #include <iostream> #include<cstdio> #include<cstring> #include<cstdlib> #include<stack> #include<qu…

题目链接:http://poj.org/problem?id=2240 题目就是要通过还钱涨自己的本钱最后还能换回到自己原来的钱种. 就是判一下有没有负环那么就直接用bellman_ford来判断有没有负环 #include <iostream> #include <cstring> #include <string> using namespace std; int n , m , s , a , b , counts; double rx , ry , cx , c…

三道题都是考察最短路算法的判环.其中1860和2240判断正环,3259判断负环. 难度都不大,可以使用Bellman-ford算法,或者SPFA算法.也有用弗洛伊德算法的,笔者还不会SF-_-…… 直接贴代码. 1860 Currency Exchange: #include <cstdio> #include <cstring> int N,M,S; double V; ; int first[maxn],vv[maxn*maxn],nxt[maxn*maxn]; double…

描述Arbitrage is the use of discrepancies in currency exchange rates to transform one unit of a currency into more than one unit of the same currency. For example, suppose that 1 US Dollar buys 0.5 British pound, 1 British pound buys 10.0 French francs…

Time Limit: 1000MS Memory Limit: 65536K Description Arbitrage is the use of discrepancies in currency exchange rates to transform one unit of a currency into more than one unit of the same currency. For example, suppose that 1 US Dollar buys 0.5 Brit…