HDU1301+prim

最小生成树。。。。

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 1 /*

 2 prim

 3 */

 4 #include<stdio.h>

 5 #include<string.h>

 6 #include<stdlib.h>

 7 #include<algorithm>

 8 #include<iostream>

 9 #include<queue>

10 #include<vector>

11 #include<map>

12 #include<math.h>

13 typedef long long ll;

14 //typedef __int64 int64;

15 const int maxn = 105;

16 const int maxm = 1005;

17 const int inf = 0x7FFFFFFF;

18 const double pi = acos(-1.0);

19 const double eps = 1e-8;

20 using namespace std;

21 

22 int mat[ maxn ][ maxn ];

23 int vis[ maxn ],dis[ maxn ];

24 

25 void prim( int n ){

26     for( int i=0;i<n;i++ ){

27         vis[ i ] = 0;

28         dis[ i ] = mat[ 0 ][ i ];

29     }

30     int res = 0;

31     vis[ 0 ] = 1;

32     for( int i=0;i<n;i++ ){

33         int k,fmin;

34         fmin = inf;

35         for( int j=0;j<n;j++ ){

36             if( vis[j]==0&&fmin>dis[ j ] ){

37                 fmin = dis[ j ];

38                 k = j;

39             }

40         }

41         if( fmin==inf ) break;

42         vis[ k ] = 1;

43         res += fmin;

44         for( int j=0;j<n;j++ ){

45             if( vis[ j ]==0&&dis[ j ]>mat[ k ][ j ] ){

46                 dis[ j ] = mat[ k ][ j ];

47             }

48         }

49     }

50     printf("%d\n",res);

51 }    

52 

53 int main(){

54     int n;

55     char a[ 4 ],b[ 4 ];

56     int k,cost;

57     while( scanf("%d",&n)==1,n ){

58         //memset( mat,0,sizeof( mat ) );

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

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

61                 mat[i][j] = inf;

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

63             scanf("%s",a);

64             scanf("%d",&k);

65             while( k-- ){

66                 scanf("%s",b);

67                 scanf("%d",&cost);

68                 mat[ a[0]-'A' ][ b[0]-'A' ] = mat[ b[0]-'A' ][ a[0]-'A' ] = cost;

69             }

70             //prim( n );

71         }

72         prim( n );

73     }

74     return 0;

75 }