样例都没过。。。。0pts求调

#include <bits/stdc++.h>
using namespace std;
vector<long long >edge[500010];
long long n,m,a,b,c,s,cnt,deep[1000010],pos[500010],ola[1000010],mn[4000010],ans,t;
void dfs(int x,int father){
	ola[++cnt]=x;
	deep[x]=deep[father]+1;
	pos[x]=cnt;
	for(int i=0;i<edge[x].size();i++){
		if(edge[x][i]==father)continue;
		dfs(edge[x][i],x);
		ola[++cnt]=x;
	}
}
void build (int v,int l,int r){
	if(l==r){
		mn[v]=ola[l];
		return;
	}
	int mid=(l+r)/2;
	build(v<<1,l,mid);
	build(v<<1|1,mid+1,r);
	if(deep[mn[v<<1]]<deep[mn[v<<1|1]])
		mn[v]=mn[v<<1];
	else
		mn[v]=mn[v<<1|1];
}
int query(int v,int l,int r,int x,int y){
	if(x<=l&&r<=y)
		return mn[v];
	int mid=(l+r)/2,k1=0,k2=0;
	if(x<=mid)
		k1=query(v<<1,l,mid,x,y);
	if(y>mid)
	    k2=query(v<<1|1,mid+1,r,x,y);
	if(deep[k1]<deep[k2])
		return k1;
	else
	    return k2;
}
int main(){
	cin>>n>>m;
	for(int i=1;i<n;i++){
		cin>>a>>b;
		edge[a].push_back(b);
		edge[b].push_back(a);
	}
	dfs(1,0); 
	build(1,1,cnt);
	deep[0]=n+1;
	while(m--){
		cin>>a>>b>>c;
		int aa,bb,cc;
		aa=a;
		bb=b;
		cc=c;
		a=pos[a],b=pos[b],c=pos[c];
		if(a>b)swap(a,b);
		if(b>c)swap(c,b);
		if(a>c)swap(a,c);
		int t1,t2,t3;
		t1=query(1,1,cnt,a,b);
		t2=query(1,1,cnt,a,c);
		t3=query(1,1,cnt,b,c);
		//cout<<"t1: "<<t1<<" t2: "<<t2<<" t3: "<<t3<<" d[a] "<<deep[aa]<<" d[b] "<<deep[bb]<<" d[c] "<<deep[cc]<<endl;
		ans=0;
		if(t1==t2)
			t=t3;
		else if(t1==t3)
			t=t2;
		else if(t2==t3)
			t=t1;
		ans=deep[aa]+deep[bb]+deep[cc]-deep[t1]-deep[t2]-deep[t3];		
		cout<<t<<" "<<ans<<endl;
	}
}