【HDU1233】还是畅通工程（MST基础题）

无坑，裸题。直接敲就恩那个AC。

 #include <iostream>
 #include <cstring>
 #include <cstdio>
 #include <cmath>
 #include <cctype>
 #include <algorithm>
 #include <numeric>

 #define typec int
 using namespace std;

 const int V = ;
 const int inf = 0xffff;
 int vis[V]; typec lowc[V], Map[V][V];

 typec prim (typec cost[][V], int n) {
     int i, j, p;
     typec minc, res = ;
     memset(vis, , sizeof(vis));
     vis[] = ;
     for (int i = ; i < n; ++ i) lowc[i] = cost[][i];
     for (int i = ; i < n; ++ i) {
         minc = inf; p = -;
         for (j = ; j < n; ++ j) {
             if ( == vis[j] && minc > lowc[j]) {
                 minc = lowc[j]; p = j;
             }
         }
         if (inf == minc) return -;
         res += minc; vis[p] = ;
         for (j = ; j < n; ++ j) {
             if ( == vis[j] && lowc[j] > cost[p][j])
             lowc[j] = cost[p][j];
         }
     }
     return res;
 }

 int main () {
     int n;
     while (~scanf("%d", &n) && n) {
         for (int i = ; i < V; ++ i) {
             for (int j = ; j < V; ++ j) {
                 if (i == j) Map[i][j] = ;
                     else Map[i][j] = inf;
             }
         }
         for (int i = ; i < n * (n - ) / ; ++i) {
             int x, y, c; scanf("%d%d%d", &x, &y, &c);
             if (x == y) continue;
             Map[x - ][y - ] = Map[y - ][x - ] = min(Map[x - ][y - ], c);
         }
         cout << prim(Map, n) << endl;
     }
     return ;
 }