HDU1217 Arbitrage (Bellman_ford)
来源:互联网 发布:c语言中char什么意思 编辑:程序博客网 时间:2024/04/28 13:47
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 pound buys 10.0 French francs, and 1 French franc buys 0.21 US dollar. Then, by converting currencies, a clever trader can start with 1 US dollar and buy 0.5 * 10.0 * 0.21 = 1.05 US dollars, making a profit of 5 percent.
Your job is to write a program that takes a list of currency exchange rates as input and then determines whether arbitrage is possible or not.
Your job is to write a program that takes a list of currency exchange rates as input and then determines whether arbitrage is possible or not.
The input file will contain one or more test cases. Om the first line of each test case there is an integer n (1<=n<=30), representing the number of different currencies. The next n lines each contain the name of one currency. Within a name no spaces will appear. The next line contains one integer m, representing the length of the table to follow. The last m lines each contain the name ci of a source currency, a real number rij which represents the exchange rate from ci to cj and a name cj of the destination currency. Exchanges which do not appear in the table are impossible.
Test cases are separated from each other by a blank line. Input is terminated by a value of zero (0) for n.
OutputTest cases are separated from each other by a blank line. Input is terminated by a value of zero (0) for n.
For each test case, print one line telling whether arbitrage is possible or not in the format "Case case: Yes" respectively "Case case: No".
Sample Input3
USDollar
BritishPound
FrenchFranc
3
USDollar 0.5 BritishPound
BritishPound 10.0 FrenchFranc
FrenchFranc 0.21 USDollar
3
USDollar
BritishPound
FrenchFranc
6
USDollar 0.5 BritishPound
USDollar 4.9 FrenchFranc
BritishPound 10.0 FrenchFranc
BritishPound 1.99 USDollar
FrenchFranc 0.09 BritishPound
FrenchFranc 0.19 USDollar 0
Case 1: Yes
Case 2: No
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
题意就是要你判断是否存在套汇现象
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////
代码:
#include<iostream>using namespace std;struct exchange{int ci,cj;double cij;}ex[1000];int i,j,k;int n,m;char name[50][20],a[50],b[50];double x;double dist[50];int flag;int ka=0;void Bellman(int v0)//核心算法 由于是要求出最大值 所以dist[]应该置为最小,0即可{flag=0;memset(dist,0,sizeof(dist));dist[v0]=1;for(k=1;k<=n;k++){for(i=0;i<m;i++){if(dist[ex[i].ci]*ex[i].cij>dist[ex[i].cj]){dist[ex[i].cj]=dist[ex[i].ci]*ex[i].cij;}}}if(dist[v0]>1.0)//flag=1;}int readcase(){scanf("%d",&n);if(n==0)return 0;for(i=0;i<n;i++)scanf("%s",name[i]);scanf("%d",&m);for(i=0;i<m;i++){scanf("%s %lf %s",a,&x,b);for(j=0;strcmp(a,name[j]);j++);//神奇的地方,同下一行for(k=0;strcmp(b,name[k]);k++);ex[i].ci=j;ex[i].cij=x;ex[i].cj=k;}return 1;}int main(){while(readcase()){for(i=0;i<n;i++){Bellman(i);if(flag)break;}if(flag)cout<<"Case "<<++ka<<": Yes"<<endl;elsecout<<"Case "<<++ka<<": No"<<endl;}return 0;}
- HDU1217 Arbitrage (Bellman_ford)
- Hdu1217 Arbitrage
- hdu1217 Arbitrage
- hdu1217 Arbitrage
- Arbitrage hdu1217 Floyd算法
- hdu1217 Arbitrage (Floyd)
- HDU1217:Arbitrage(SPFA)
- hdu1217 Arbitrage(SPFA判负环)
- HDU1217:Arbitrage(SPFA)
- HDU1217 Arbitrage 【SPFA】
- hdu1217——Arbitrage
- HDU1217 Arbitrage Floyd算法
- 【floyed】【HDU1217】【Arbitrage】
- hdu1217 Arbitrage (floyd)
- hdu1217 Arbitrage(Floyd)
- HDU1217(bellman_ford判环)
- HDU1217——Arbitrage(Floyd)
- hdu1217—Arbitrage(floyed)
- CLisp 9:获取系统环境变量,执行外部程序
- C语言面向对象-类
- On Knowledge Inflation: 知识通胀时代来临, 及为什么员工动力不足是伪命题
- SGU 441 Set Division(矩阵,斯特灵数)
- JMS开发指南
- HDU1217 Arbitrage (Bellman_ford)
- Visual C++界面美化(1)
- 我谈阶梯博弈(Staircase Nim)
- erlang Atoms
- jms需要注意
- Java: Queue
- 多重网络 锐捷
- SQLPLUS使用技巧
- static关键字