为什么编译失败。。。。。。

RT

#include <iostream>
#include <cstdio>
#include <queue>
using namespace std;
struct bb
{
    int to=-1;
    int from=-1;
    int lon=0;
    int nex=-1;
}bian[200001];
struct kc
{
    int last=-1;
    int fir=-1;
    int num=0;
}head[200001];
int p=0;
void lian(int a,int b,int c)
{
    p++;
    if(head[a].num)
    {
        bian[head[a].last].nex=p;
        bian[p].from=a;
        bian[p].to=b;
        bian[p].lon=c;
        head[a].num++;
        head[a].last=p;
    }
    else
    {
        head[a].fir=p;
        head[a].last=p;
        head[a].num++;
        bian[p].from=a;
        bian[p].to=b;
        bian[p].lon=c;
    }
}
priority_queue<pair<int,int>>q;
int n;
int dis[100001]={};
bool use[100001]={};
int ans=0;
int cnt=0;
void prim()
{

    q.push(make_pair(0,1));
    for(int i=0;i<=n;i++)
    {
        dis[i]=9999999;
    }
    dis[1]=0;
    while(!q.empty()&&cnt<n)
    {

        int ask=q.top().first;
        int x=q.top().second;
        q.pop();

        if(use[x])
        {
            continue;
        }
        ans+=ask;
        cnt++;
        use[x]=1;
        int f=head[x].fir;

        for(int i=1;i<=head[x].num;i++)
        {

            if(dis[bian[f].to]>bian[f].lon)
            {
                dis[bian[f].to]=bian[f].lon;
                q.push(make_pair(-dis[bian[f].to],bian[f].to));
            }
            f=bian[f].nex;
        }
    }
}
int main()
{
    int m;
    scanf("%d %d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        int a,b,c;
        scanf("%d %d %d",&a,&b,&c);
        lian(a,b,c);
        lian(b,a,c);
    }
    prim();
    if(cnt==n)
    printf("%d",ans*(-1));
    else
        printf("orz");
    return 0;
}