最小生成树_prim

<pre name="code" class="cpp"><pre name="code" class="cpp">#include<cstdio>
#include<iostream>
#define inf 88888888
using namespace std;
int map[500][500],path[505];
int n;
void prim(int x)
{
    int dis[101],i,j,k,minn;
    for(i=1;i<=n;i++)
    {dis[i]=map[i][x];path[i]=x;}
    for(i=1;i<=n-1;i++)
    {
    	minn=inf;
    	for(j=1;j<=n;j++)
    	if((dis[j]!=0)&&(dis[j]<minn))
        {minn=dis[j];k=j;};
        dis[k]=0;
        for(j=1;j<=n;j++)
        if(dis[j]>map[j][k])
        {dis[j]=map[j][k];path[j]=k;}
    }
}
int main(){
	int i,j,x,y,len,tot=0,m;
	char ch;
	cin>>n;
	for(i=1;i<=n;i++)//初始化 
	for(j=1;j<=n;j++)
	if(i!=j)map[i][j]=inf;
	for(i=1;i<=n-1;i++)//init
	{
		cin>>ch;scanf("%d",&m);
		x=int(ch)-int('A')+1;
		for(j=1;j<=m;j++)
		{
			cin>>ch;scanf("%d",&len);
			y=int(ch)-int('A')+1;
			map[x][y]=len;
			map[y][x]=len;
		}
	}
	prim(1);
	for(i=1;i<=n;i++)
	{
		if(path[i]!=i)
		{
			tot=tot+map[i][path[i]];
		}
	}
	cout<<tot;
}