hdu1102 Constructing Roads 基础最小生成树

 //克鲁斯卡尔（最小生成树）
 #include<cstdio>
 #include<iostream>
 #include<algorithm>
 using namespace std;

 const int maxn = ;
 int n, t;
 struct node
 {
     int bagin, end, len;
 }arr[maxn];
 int fa[maxn];

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

 bool cmp(node a, node b)
 {
     return a.len<b.len;
 }

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

 int main()
 {
     while (cin >> n)
     {
         t = ;
         for (int i = ; i <= n; i++)
         {
             for (int j = ; j <= n; j++)
             {
                 int x;
                 cin >> x;
                 arr[t].bagin = i; arr[t].end = j; arr[t].len = x;
                 t++;
             }
         }
         sort(arr, arr + t, cmp);
         init();
         int m;
         cin >> m;
         while (m--)
         {
             int a, b;
             cin >> a >> b;
             int fx, fy;
             fx = find(a); fy = find(b);
             fa[fy] = fx;
         }
         int ans = ;
         for (int i = ; i<t; i++)
         {
             int fx, fy;
             fx = find(arr[i].bagin);
             fy = find(arr[i].end);
             if (fx != fy)
             {
                 ans += arr[i].len;
                 fa[fy] = fx;
             }
         }
         cout << ans << endl;
     }
     return ;
 }