Agri-Net POJ 1258(最小生成树模板)

 1 #include <iostream>
 2 #include <algorithm>
 3 #include <utility>
 4 #include <cstdio>
 5 #include <cmath>
 6 #include <cstring>
 7 #include <string>
 8 #include <vector>
 9 #include <stack>
10 #include <queue>
11 #include <map>
12 #include <set>
13 
14 using namespace std;
15 typedef long long LL;
16 const int INF_INT=0x3f3f3f3f;
17 const LL INF_LL=0x3f3f3f3f3f3f3f3f;
18 
19 typedef pair<int,int> P;
20 
21 int n;
22 int edge[100][100];
23 bool used[100];
24 
25 int prim()
26 {
27     for(int i=0;i<n;i++) used[i]=false;
28     int ans=0;
29     priority_queue<P,vector<P>,greater<P> > que;
30     for(int i=1;i<n;i++) que.push(P(edge[0][i],i));
31     used[0]=true;
32     while(que.size())
33     {
34         P p=que.top();que.pop();
35         if(used[p.second]) continue;
36         used[p.second]=true;
37         ans+=p.first;
38         for(int i=0;i<n;i++)
39         if(!used[i]) que.push(P(edge[p.second][i],i));
40     }
41     return ans;
42 }
43 
44 int main()
45 {
46 //    freopen("black.in","r",stdin);
47 //    freopen("black.out","w",stdout);
48     while(~scanf("%d",&n))
49     {
50         for(int i=0;i<n;i++)
51             for(int j=0;j<n;j++) scanf("%d",&edge[i][j]);
52         printf("%d\n",prim());
53     }
54     return 0;
55 }