poj 2240

#include<iostream>
#include<cstring>
using namespace std;
double map[111][111];
char s[33][111];
int n;
int get(char s1[])
{
for(int i=1;i<=n;i++)
if(strcmp(s[i],s1)==0) return i;
}
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(map[i][k]*map[k][j]>map[i][j])
map[i][j]=map[i][k]*map[k][j];
}
for(i=1;i<=n;i++)
if(map[i][i]>1) return true;
return false;
}
int main()
{
int i,m;
double rate;
char s1[111],s2[111];
int cas=0;
while(scanf("%d",&n)!=EOF)
{
cas++;
if(n==0) break;
memset(map,0,sizeof(map));
for(i=1;i<=n;i++)
cin>>s[i];
cin>>m;
while(m--)
{
cin>>s1>>rate>>s2;
int u=get(s1);
int v=get(s2);
map[u][v]=rate;
}
if(floyd())
printf("Case %d: Yes\n",cas);

else printf("Case %d: No\n",cas);
}
return 0;
}