NYOJ 布线问题 prim

 //普通邻接矩阵  时间复杂度 O(v*e)
#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define INF 999999
int v;
int map[505][505];
int lowcost[505];
int visit[1000];
int prim( int start )
{
	int min, choose, ans;
	ans = 0;
	for( int i = 1; i <= v; i++ )
	{
		lowcost[i] = map[start][i];
	}
	lowcost[start] = 0;
	visit[start] = 1;
	for( int i = 1; i <= v-1; i++ )
	{
		min = INF;
		for( int j = 1; j <= v; j++ )
		{
			if( !visit[j] && lowcost[j] >= 0 && lowcost[j] < min )
			{
				min = lowcost[j];
				choose = j;
			}
		}
		ans += lowcost[choose];
		visit[choose] = 1;
		for( int j = 1; j <= v; j++ )
		{
			if( !visit[j] && map[choose][j] < lowcost[j] )
				lowcost[j] = map[choose][j];						
		}
	}
	return ans;	
}
int main( )
{
	
	int T, e, min, a, b, w, num;
	scanf( "%d", &T );
	while( T-- )
	{
		memset( map, 0, sizeof(map) );
		memset( visit, 0, sizeof(visit) );
		memset( lowcost, -1, sizeof(lowcost) );	
		scanf( "%d%d", &v, &e );
		for( int i = 0; i < e; i++ )
		{
			scanf( "%d %d %d\n", &a, &b, &w );
			if( map[a][b] )
			{
				if( map[a][b] > w )
				{
					map[a][b] = w;
					map[b][a] = w;
				}
			}
			else
			{
				map[a][b] = w;
				map[b][a] = w;
			}
		}
		min = INF;
		for( int i = 0; i < v; i++ )
		{
			scanf( "%d", &num );
			if( num < min )
				min = num;
		}
		printf( "%d\n", min+prim( 1 ) );		
	}
	return 0;
}  
                                     

优先队列+邻接矩阵  优先队列 时间复杂度  O( nlog(n) )

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <queue>
#define MAX 505
#define INF 9999999
#define CLR(arr,val) memset(arr,val,sizeof(arr))

using namespace std;
typedef struct a
{
	int dis, v;
	friend bool operator < ( const struct a &n1, const struct a &n2 )
	{
		return n1.dis > n2.dis;
	}
}node;
int n;
int map[MAX][MAX];
int vis[MAX];
int lowcost[MAX];
inline void init()
{
    for( int i = 0; i < MAX; i++ )
    {
        lowcost[i] = INF;
        for( int j = 0; j < MAX; j++ )
            map[i][j] = INF;
    }
    CLR( vis, 0 );  
};
int prim( int start )
{
	int sum = 0;
	node pre, cur;
	priority_queue<node> Q;
	lowcost[start] = 0;
	pre.dis = 0;
	pre.v = start;
	Q.push( pre );
	while( !Q.empty() )
	{
		pre = Q.top();
		Q.pop();
		if( vis[pre.v] )
			continue;
		sum += pre.dis;
		vis[pre.v] = 1;
		for( int i = 1; i <= n; i++ )
		{
			if( !vis[i] &&  map[pre.v][i] < lowcost[i] )
			{
				lowcost[i] = map[pre.v][i];
				cur.dis = lowcost[i];
				cur.v = i;
				Q.push( cur );
			}
		}
	}
	return sum;
}
int main()
{
    int T, e, a, b, w, num, min;
    scanf( "%d", &T );  
    while( T-- )  
    {  
    	init();
        scanf( "%d%d", &n, &e );  
        for( int i = 0; i < e; i++ )  
        {  
            scanf( "%d %d %d\n", &a, &b, &w );  
            if( map[a][b] )  
            {  
                if( map[a][b] > w )  
                {  
                    map[a][b] = w;  
                    map[b][a] = w;  
                }  
            }  
            else  
            {  
                map[a][b] = w;  
                map[b][a] = w;  
            }  
        }  
        min = INF;  
        for( int i = 0; i < n; i++ )  
        {  
            scanf( "%d", &num );  
            if( num < min )  
                min = num;  
        } 
        printf( "%d\n", prim( 1 ) + min );
    }
	return 0;
}