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;
}