NYOJ188_Arbitrage(BellmanFord)

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#include<stdio.h>#include<string>#include<map>using namespace std;map<string,int>mp;double a[40][40];int n;void addEdge(char str1[],double x,char str2[]){string s1=str1;string s2=str2;int u,v;u=mp[s1];v=mp[s2];a[u][v]=x;}bool floyd(){int i,j,k;for(k=1;k<=n;k++)for(i=1;i<=n;i++)for(j=1;j<=n;j++){if(a[i][j]<a[i][k]*a[k][j]){a[i][j]=a[i][k]*a[k][j];}}for(i=1;i<=n;i++){if(a[i][i]>1)return true;}return false;}int main(){int m,i,j,count,t=0;double x;char str[20],str1[20],str2[20];while(scanf("%d",&n)&&n){count=0;mp.clear();getchar();for(i=1;i<=n;i++)for(j=1;j<=n;j++){if(i==j)a[i][j]=1;elsea[i][j]=0;}for(i=0;i<n;i++){scanf("%s",str);string s=str;mp[s]=++count;}scanf("%d",&m);getchar();for(i=0;i<m;i++){scanf("%s%lf%s",str1,&x,str2);addEdge(str1,x,str2);}if(floyd())printf("Case %d: Yes\n",++t);elseprintf("Case %d: No\n",++t);}return 0;}