90分?(#2wa)

#include<cstdio>
#include<algorithm>
using namespace std;
struct edg{
    int from,w,to;
}edge[200001];
int cnt,fa[200001];
bool cmp(edg a,edg b)
{
    return a.w<b.w;
}
int gf(int a)
{
    if(fa[a]!=a)
        return fa[a]=gf(fa[a]);
    else
        return a;
}
void hb(int a,int b){
    int f1,f2;
    f1=gf(a);
    f2=gf(b);
    if(f1!=f2)
            fa[f2]=f1;
    return;
}
int judge(int a,int b){
    int f1,f2;
    f1=gf(a);
    f2=gf(b);
    if(f1==f2)return 1;
    return 0;
}
int main()
{
    int a,b,c,i,j=0,n,m,ans=0;	
    scanf("%d%d",&n,&m);
    ans=n;
    for(i=1;i<=n;i++)
        fa[i]=i;
    for(i=1;i<=m;i++)
        scanf("%d%d%d",&edge[i].from ,&edge[i].to,&edge[i].w);
    sort(edge+1,edge+m+1,cmp);
    for(i=1;i<=m;i++)
    {
        
        if(!judge(edge[i].from,edge[i].to))
        {
            hb(edge[i].from,edge[i].to);
            j++;
        }
		if(j==n-1)
        {
        printf("%d",edge[i-1].w);
        return 0;
        }
    }
    printf("-1");
    return 0;
 }   ```