HDU 2066最短路径Dijkstra、

思路：枚举所有起点城市然后比较每个起点所去喜欢城市的最小距离

 #include<cstdio>
 #include<cmath>
 #include<cstring>
 const int qq=+;
 const int MAX=1e7;
 int s[qq],e[qq];
 int dist[qq];
 int vis[qq],tar[qq];
 int city[qq][qq];
 int t,a,b;
 void Dijkstra()
 {
     int poor=MAX;
     for(int l=;l<=a;++l){
         int tot=MAX;
         for(int i=;i<qq;++i){
             vis[i]=;
             dist[i]=city[s[l]][i];
         }
         vis[s[l]]=;
         for(int i=;i<qq;++i){
             int minx=MAX;
             int u=s[l];
             for(int j=;j<qq;++j)
                 if(!vis[j] && dist[j] < minx)
                     minx=dist[u=j];
             if(minx==MAX)    break;
             vis[u]=;
             if(tar[u]!=){
                 tot=dist[u];
                 break;
             }
             for(int j=;j<qq;++j)
                 if(!vis[j] && city[u][j] < MAX)
                     if(dist[u]+city[u][j]<dist[j])
                         dist[j] = dist[u] + city[u][j];
         }
         if(tot<poor)
             poor=tot;
     }
     printf("%d\n",poor);
 }
 int main()
 {
     while(scanf("%d %d %d",&t,&a,&b)!=EOF){
         for(int j,i=;i<qq;++i)
             for(j=;j<qq;++j)
                 city[i][j]=MAX;
         for(int i=;i<=t;++i){
             int x,y,cost;
             scanf("%d %d %d",&x,&y,&cost);
             if(cost<city[x][y])
                 city[x][y]=city[y][x]=cost;
         }
         for(int i=;i<=a;++i)
             scanf("%d",&s[i]);
         memset(tar,,sizeof(tar));
         for(int i=;i<=b;++i){
             int ans;scanf("%d",&ans);
             tar[ans]=;
         }
         Dijkstra();
     }
 }