hdu 1596 find the safest road

#include<iostream>#include<cstring>#include<cstdio>#include<algorithm>using namespace std;double map[1100][1100];void floyd(int n){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][j]<map[i][k]*map[k][j])map[i][j]=map[i][k]*map[k][j];}}int main(){int n;int i,j;while(scanf("%d",&n)!=EOF){for(i=1;i<=n;i++){for(j=1;j<=n;j++){scanf("%lf",&map[i][j]);}}floyd(n);int Q;int a,b;scanf("%d",&Q);for(i=1;i<=Q;i++){scanf("%d%d",&a,&b);if(map[a][b]>0)printf("%.3lf\n",map[a][b]);elseprintf("What a pity!\n");}}}