Constructing Roads POJ - 2421

 1 #include <stdio.h>
 2 #include <iostream>
 3 #include <queue>
 4 using namespace std;
 5 
 6 const int inf = (int)1e9;
 7 const int N = 110;
 8 int g[N][N];
 9 int dis[N];
10 bool vis[N];
11 int n;
12 
13 struct node{
14     int loc;
15     int v;
16 
17     bool friend operator<(const node& a,const node& b){
18         return a.v > b.v;
19     }
20 };
21 
22 priority_queue<node > que;
23 
24 int prime(){
25 
26     que.push(node{1,0});
27     dis[1] = 0;
28 
29     while(!que.empty()){
30         int u = que.top().loc;
31         que.pop();
32 
33         vis[u] = true;
34 
35         for(int v = 1; v <= n; v++){
36             if(!vis[v] && dis[v] > g[u][v]){
37                 dis[v] = g[u][v];
38                 que.push(node{v,dis[v]});
39             }
40         }
41     }
42 
43     int ans = 0;
44     for(int i = 1; i <= n; i++){
45 
46     //    printf("%d ",dis[i]);
47         ans += dis[i];
48     }
49 
50    // printf("\n");
51 
52     return ans;
53 }
54 
55 int main(){
56 
57     scanf("%d",&n);
58 
59     for(int i = 1; i <= n; i++)
60         for(int j = 1; j <= n; j++)
61             scanf("%d",&g[i][j]);
62 
63     for(int i = 1; i <= n; i++)
64         dis[i] = inf;
65 
66     int m;
67     scanf("%d",&m);
68 
69     int u,v;
70     for(int i = 1; i <= m; i++){
71         scanf("%d%d",&u,&v);
72         g[u][v] = g[v][u] = 0;//已经有路的村庄
73     }
74 
75     printf("%d\n",prime());
76 
77     return 0;
78 }