poj 1258 Agri-Net

简单的模板题：prim算法适合浓密图：

 1 #include<stdio.h>

 2 #include<string.h>

 3 #define MAXN 110

 4 #define INF 100000000

 5 

 6 int n, v[MAXN], low[MAXN], w[MAXN][MAXN];

 7 

 8 void solve()

 9 {

10         int ans = 0;

11         memset(v,0,sizeof(v));

12         v[0] = 1;

13         for(int i = 1; i < n; i ++) low[i] = w[0][i];

14         for(int i = 0; i < n-1; i ++)

15         {

16             int min = INF, p;

17             for(int j = 0; j < n; j ++)

18                 if(!v[j] && low[j] < min) min = low[j], p = j;

19             v[p] = 1;

20             ans += min;

21             for(int j = 0; j < n; j ++)

22                 if(!v[j] && low[j] > w[p][j]) low[j] = w[p][j];

23         }

24         printf("%d\n",ans);

25 }

26 

27 int main()

28 {

29     while(~scanf("%d",&n))

30     {

31         for(int i = 0; i < n; i ++)

32             for(int j = 0; j < n; j ++)

33             {

34                 int a;

35                 scanf("%d",&a);

36                 w[i][j] = a;

37             }

38             solve();

39     }

40     return 0;

41 }