题目链接: https://vjudge.net/problem/POJ-2240 题目大意: 已知n种货币,以及m种货币汇率及方式,问能否通过货币转换,使得财富增加. 思路: 由于这里问的是财富有没有增加,但是没有源点,所以可以枚举1-n为源点,分别用bellman-ford算法判断是否存在正环,如果有正环那就输出Yes,反之输出No. 这里还需要编号 其实可以用Floyd算法直接出结果判断有没有正环,这里用bellman-ford是卡着时间过的. #include<iostream> #i…

题目链接:https://cn.vjudge.net/problem/POJ-2240 题意 套利(Arbitrage)就是通过不断兑换外币,使得自己钱变多的行为 给出一些汇率 问能不能套利 思路 马上想到bellman的判负圈 于是写完WA一发 问题在是否联通的问题上,我随便给Bellman喂了一个节点... 然后有连续WA了5次,问题在我把Yes打成了YES... 图论题目一定要考虑连通性,至少是查负环时 注意预处理 以后再也别手打输出了,就算是天塌下来也别 代码 #include <map…

Arbitrage Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 30790   Accepted: 12761 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 curren…

Arbitrage poj-2240 #include<iostream> #include<cstdio> #include<cstring> #include<string> #include<algorithm> #include<cmath> #include<map> using namespace std; map<string,int>ma; int n; int m; float graph[3…

//Accepted 732 KB 782 ms //floyd应用 #include <cstdio> #include <cstring> #include <iostream> #include <queue> #include <cmath> #include <map> #include <algorithm> using namespace std; /** * This is a documentation…

Arbitrage Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 17360   Accepted: 7308 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…

跑完Floyd后,d[u][u]就表示从u点出发可以经过所有n个点回到u点的最短路,因此只要根据数组对角线的信息就能判断是否存在负环. #include<cstdio> #include<cstring> #include<iostream> #include<string> #include<algorithm> using namespace std; int n; ][]; void Floyd(){ ; k<n; ++k){ ; i…

Arbitrage Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 15640   Accepted: 6563 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…

题意:与poj1680一样,有不同的换钱渠道,可以完成特定两种货币的交换,并且有汇率,只不过此题是单向边,然后问是否能使财富增加 与poj1680一样,建图之后直接spfa判增值的环即可 #include<iostream> #include<cstdio> #include<string> #include<cstring> #include<queue> #include<map> #include<vector> u…

Arbitrage DescriptionArbitrage 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…