hud3371 Connect the Cities 简单最小生成树

 //我看过Discuss说不能用克鲁斯卡尔因为有很多边
 //但是只能用G++过，C++的确超时
 #include <stdio.h>
 #include <string.h>
 #include <algorithm>
 using namespace std;

 struct node
 {
     int a, b, cost;
 }c[];
 int fa[];

 void init(int n)
 {
     for (int i = ; i <= n; i++)
         fa[i] = i;
 }

 bool cmp(node x, node y)
 {
     return x.cost<y.cost;
 }

 int find(int x)
 {
     if (fa[x] != x) fa[x] = find(fa[x]);
     return fa[x];
 }

 int main()
 {
     int n, k, m, ncase;
     scanf("%d", &ncase);
     while (ncase--)
     {
         scanf("%d %d %d", &n, &k, &m);
         init(n);    //初始化
         for (int i = ; i<k; i++)
             scanf("%d %d %d", &c[i].a, &c[i].b, &c[i].cost);
         for (int i = ; i <= m; i++)
         {
             int x, pos, pos1;
             scanf("%d %d", &x, &pos);
             for (int j = ; j<x; j++)
             {
                 scanf("%d", &pos1);
                 c[k].a = pos, c[k].b = pos1, c[k].cost = ;
                 pos = pos1;
                 k++;
             }
         }

         sort(c, c + k, cmp);
         int sum = ;
         for (int i = ; i<k; i++)
         {
             int x = find(c[i].a);
             int y = find(c[i].b);
             if (x != y)
                 sum += c[i].cost, fa[x] = y;
         }

         int count = ;
         for (int i = ; i <= n; i++)
         if (fa[i] == i)
             count++;

         if (count != )
             printf("-1\n");
         else
             printf("%d\n", sum);
     }
     return ;
 }