学步园

#include<iostream>
#include<map>
#include<vector>
#include<string>
#include<algorithm>
using namespace std;
const int maxn=111;
int n,m;
map<string,int>mp;
string s[maxn];
string s1,s2;
double g[maxn][maxn];
bool can[maxn][maxn];
int x,y,cas;
double temp;
bool vis[maxn];
bool floyd()
{
    for(int k=1;k<=n;k++)
    {
        for(int i=1;i<=n;i++)
        {
            if(!g[i][k]) continue;
            if(g[i][i] > 1.0)
            {
                return true;
            }
            for (int j=1; j<=n; j++)
            {
                if ( !g[k][j] ) continue;
                temp= g[i][k] * g[k][j];
                if ( temp > g[i][j] )
                {
                    g[i][j] = temp;
                }
            }
        }
    }
    return false;
}
int main()
{
    cas=1;
    while(cin>>n)
    {
        memset(g,0,sizeof(g));
        memset(vis,0,sizeof(vis));
        memset(can,0,sizeof(can));
        mp.clear();
        if(!n)
        {
            break;
        }
        for(int i=1;i<=n;i++)
        {
            cin>>s[i];
            mp[s[i]]=i;
        }
        cin>>m;
        for(int i=1;i<=m;i++)
        {
            cin>>s1>>temp>>s2;
            x=mp[s1];
            y=mp[s2];
            g[x][y]=temp;
            can[x][y]=true;
        }
        cout<<"Case "<<cas++<<": ";
        if(floyd())
        {
            cout<<"Yes"<<endl;
        }
        else
        {
            cout<<"No"<<endl;
        }
    }
    return 0;
}