prim生成树

# include<iostream>
# include<deque>
# include<vector>
# include<map>
# include<queue>
# include<cstring>

using namespace std;
typedef long long int ll;


ll inf=(1ll<<50);
int n,m;

ll ans;
ll nowdis[5050];

typedef struct
{
    int b,e;

    ll w;
} xinxi;

xinxi s[200000*3+10];
int len;
int f[200000*3+10];
int nex[200000*3+10];

void add(int x,int y,int z)
{
    s[len].b=x;
    s[len].e=y;
    s[len].w=z;

    nex[len]=f[x];
    f[x]=len;
    len++;

}
void  prim()
{

    int x=f[1];

    for(int i=2;i<=n;i++)
    {
        nowdis[i]=inf;

    }
    while(x!=-1)
    {
        int j=s[x].e;

        nowdis[j]=min(nowdis[j],s[x].w);

        x=nex[x];

    }
    for(int i=2; i<=n; i++)
    {
        ll minn=inf;

        int id=0;

        for(int j=2; j<=n; j++)
        {

            if(nowdis[j]<minn&&nowdis[j])
            {
                minn=nowdis[j];

                id=j;
            }
        }

        ans+=minn;

        nowdis[id]=0;

        int x=f[id];

        while(x!=-1)
        {
            int j=s[x].e;


            if(s[x].w<nowdis[j])
            {
                nowdis[j]=s[x].w;
            }

            x=nex[x];

        }


    }
}
int main ()
{



    memset(f,-1,sizeof(f));

    cin>>n>>m;



    for(int i=1; i<=m; i++)
    {
        int x,y;

        ll z;

        cin>>x>>y>>z;

        add(x,y,z);

        add(y,x,z);
    }

    prim();

    for(int i=1;i<=n;i++)
    {
        if(nowdis[i])
        {
            cout<<"orz";
            
            return 0;
            
        }
    }

    cout<<ans;
    return 0;


}