HDU 1596 也是最小路径Dijkstra

 #include<cstdio>
 #include<cmath>
 #include<cstring>
 const int qq=+;
 double dist[qq];
 double city[qq][qq];
 int vis[qq];
 int n,m;
 int s,e;
 void Dijkstra()
 {
     double MAX;
     int u;
     for(int i=;i<=n;++i){
         vis[i]=;
         dist[i]=city[s][i];
     }
     vis[s]=;
     for(int l=;l<=n;++l){
         MAX=;u=s;
         for(int i=;i<=n;++i)
             if(!vis[i] && dist[i] > MAX)
                 MAX = dist[u=i];
         if(MAX==)    break;
         if(u==e)    break;
         vis[u]=;
         for(int i=;i<=n;++i)
             if(!vis[i]){
                 if(dist[i]<dist[u]*city[u][i])
                     dist[i]=dist[u]*city[u][i];
                 if(dist[i]<dist[u]*city[i][u])
                     dist[i]=dist[u]*city[u][i];
             }

     }
     if(u!=e)    printf("What a pity!\n");
     else            printf("%.3lf\n",dist[e]);
 }
 int main()
 {
     while(~scanf("%d",&n)){
         for(int j,i=;i<=n;++i)
             for(j=;j<=n;++j)
                 scanf("%lf",&city[i][j]);
         scanf("%d",&m);
         for(int i=;i<m;++i){
             scanf("%d %d",&s,&e);
             Dijkstra();
         }
     }
 } 

将原来的+换成*就行了、模板懂了这题就是水题了