HDU1301+prim

最小生成树。。。。

/*
prim
*/
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<algorithm>
#include<iostream>
#include<queue>
#include<vector>
#include<map>
#include<math.h>
typedef long long ll;
//typedef __int64 int64;
const int maxn = 105;
const int maxm = 1005;
const int inf = 0x7FFFFFFF;
const double pi = acos(-1.0);
const double eps = 1e-8;
using namespace std;

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

void prim( int n ){
    for( int i=0;i<n;i++ ){
        vis[ i ] = 0;
        dis[ i ] = mat[ 0 ][ i ];
    }
    int res = 0;
    vis[ 0 ] = 1;
    for( int i=0;i<n;i++ ){
        int k,fmin;
        fmin = inf;
        for( int j=0;j<n;j++ ){
            if( vis[j]==0&&fmin>dis[ j ] ){
                fmin = dis[ j ];
                k = j;
            }
        }
        if( fmin==inf ) break;
        vis[ k ] = 1;
        res += fmin;
        for( int j=0;j<n;j++ ){
            if( vis[ j ]==0&&dis[ j ]>mat[ k ][ j ] ){
                dis[ j ] = mat[ k ][ j ];
            }
        }
    }
    printf("%d\n",res);
}    

int main(){
    int n;
    char a[ 4 ],b[ 4 ];
    int k,cost;
    while( scanf("%d",&n)==1,n ){
        //memset( mat,0,sizeof( mat ) );
        for( int i=0;i<n;i++ )
            for( int j=0;j<n;j++ )
                mat[i][j] = inf;
        for( int i=0;i<n-1;i++ ){
            scanf("%s",a);
            scanf("%d",&k);
            while( k-- ){
                scanf("%s",b);
                scanf("%d",&cost);
                mat[ a[0]-'A' ][ b[0]-'A' ] = mat[ b[0]-'A' ][ a[0]-'A' ] = cost;
            }
            //prim( n );
        }
        prim( n );
    }
    return 0;
}