hdu1102 Constructing Roads (简单最小生成树Prim算法)

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 
 6 using namespace std;
 7 
 8 #define inf 99999999
 9 
10 int map[105][105],path,node[105],vis[105],n;
11 
12 void Prim()
13 {
14     int ans=1;
15     vis[1]=1;
16     node[1]=0;
17     for(int k=1;k<=n;k++)
18     {
19         int minn=inf;
20         for(int i=1;i<=n;i++)
21         if(!vis[i]&&minn>node[i])
22         {
23             minn=node[i];
24             ans=i;
25         }
26         vis[ans]=1;
27         path+=node[ans];
28 
29         for(int i=1;i<=n;i++)
30         {
31             if(!vis[i]&&node[i]>map[ans][i])
32             node[i]=map[ans][i];
33         }
34     }
35 }
36 
37 int main()
38 {
39     while(cin>>n)
40     {
41         for(int i=1;i<=n;i++)
42         {
43             node[i]=inf;vis[i]=0;
44             for(int j=1;j<=n;j++)
45             cin>>map[i][j];
46         }
47         int m;
48         cin>>m;
49         while(m--)
50         {
51             int a,b;
52             cin>>a>>b;
53             map[a][b]=map[b][a]=0;
54         }
55         path=0;
56         Prim();
57         cout<<path<<endl;
58     }
59     return 0;
60 }