【HDU1879】继续畅通工程（MST基础题）

真心大水题。。。不多说。

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

 #define typec int
 using namespace std;

 const typec inf = 0xffff;
 const int V = ;
 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 (i = ; i < n; ++ i) lowc[i] = cost[][i];
     for (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)) {
         if (!n) break;
         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, w, ok;
             scanf("%d%d%d%d", &x, &y, &w, &ok);
             if (!ok) {
                 Map[x - ][y - ] = Map[y - ][x - ] = min(Map[x][y], w);
             } else {
                 Map[x - ][y - ] = Map[y - ][x - ] = ;
             }
         }

         cout << prim(Map, n) << endl;
     }
     return ;
 }