hdu 1596

#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
#define N 1005
#define INF 0x3f3f3f3f
double dis[N][N],d[N];
double vis[N];
double  dijkstral(int v0,int n,int t)
{
    int i,x,y;
    double temp;
    for(i = 1 ; i <= n ; i++)
    {
        d[i] = dis[v0][i];
        vis[i] = 0;
    }
    d[v0] = 1.0;
    vis[v0] = 1;
    for(i = 1 ; i <= n ; i++)
    {
        temp = 0.0 ;
        for(y = 1 ; y <= n ; y++)
           if(!vis[y] && temp<d[y]) temp = d[x=y];
        if(temp == 0.0) return d[t];
            vis[x] = 1;
        for(y = 1 ; y <= n ; y++)
            if(!vis[y] &&dis[x][y]*d[x]>d[y])
                d[y] = d[x]*dis[x][y];
    }
    return d[t];
}
int main()
{
    int n,q,i,j,s,t;
    while(~scanf("%d",&n))
    {
        for(i = 1 ; i <= n ; i++)
            for(j = 1 ; j <= n ; j++)
            scanf("%lf",&dis[i][j]);
            scanf("%d",&q);
            while(q--)
            {
                scanf("%d %d",&s,&t);
                double ans = dijkstral(s,n,t);
                if(ans == 0.0) printf("What a pity!
");
                else printf("%.3lf
",ans);
            }
    }
    return 0;
}