Arbitrage(floyd)

http://poj.org/problem?id=2240

#include <stdio.h>
#include <string.h>
const int INF=1<<28;
double dis[50][50];
char str[102][202];
int n,m;

void init()
{
    for (int i = 0; i <= n; i ++)
    {
        for (int j = 0; j <= n; j ++)
        {
            dis[i][j] = 1;
        }
    }
}
int Deal(char *s)
{
    for (int i = 1; i <= n; i ++)
    {
        if (!strcmp(s,str[i]))
            return i;
    }
    return 0;
}
void floyd()
{
    for (int k = 1; k <= n; k ++)
    {
        for (int i = 1; i <= n; i ++)
        {
            for (int j = 1; j <= n; j ++)
            {
                if (dis[i][j] < dis[i][k]*dis[k][j])
                    dis[i][j] = dis[i][k]*dis[k][j];
            }
        }
    }

}
int main()
{
    int o = 0;
    while(~scanf("%d%*c",&n)&&n)
    {
        ++o;
        char ss[202],ss1[202];
        double rate;
        init();
        for (int i = 1; i <= n; i ++)
        {
            scanf("%s",str[i]);
        }
        scanf("%d%*c",&m);
        while(m--)
        {
            scanf("%s",ss);
            int i = Deal(ss);
            scanf("%lf",&rate);
            scanf("%s",ss1);
            int j = Deal(ss1);
            dis[i][j] = rate;
        }
        floyd();
        int flag = 0;
        for (int i = 1; i <= n; i ++)
        {
            if (dis[i][i] > 1)
                flag = 1;
        }
        if (flag)
            printf("Case %d: Yes
",o);
        else
            printf("Case %d: No
",o);
    }
    return 0;
}