#include<bits/stdc++.h>
//#include "meetings.h"
using namespace std;
typedef int ll;
typedef pair<ll,ll> pll;
typedef long double ld;
const ll MOD=1e9+7;
const ll N=2e3+5;
const ld pi=3.14159265359;
#define REP(i,n) for(ll i=0;i<n;i++)
#define REP1(i,n) for(ll i=1;i<=n;i++)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define setp setprecision
#define lwb lower_bound
#define SZ(a) (ll)a.size()
vector<pll> ed;
vector<ll> dg[N];
/*
int Query(ll a,ll b,ll c);
void Bridge(ll a,ll b);
*/
void build(ll nl,ll nr,vector<ll> v){
vector<ll> l,r,midr,midl,line;
l.clear();r.clear();midr.clear();midl.clear();line.clear();
ll id=N-1;
for(ll i:v){
ll x=Query(nl,nr,i);
if(x==nl){
l.pb(i);
}else if(x==nr){
r.pb(i);
}else{
if(x==i)line.pb(i);
dg[x].pb(i);
id=(SZ(dg[x])>SZ(dg[id])?x:id);
}
}
if(SZ(line)==0){ed.pb(mp(nl,nr));}
for(ll i:line){
if(i==id){
for(ll j:dg[i]){
if(j!=i)midl.pb(j);
}
continue;
}
ll x=Query(nl,id,i);
if(x==i){
for(ll j:dg[i])midl.pb(j);
}else{
for(ll j:dg[i])midr.pb(j);
}
}
for(ll i:line)dg[i].clear();
random_shuffle(l.begin(),l.end());
random_shuffle(r.begin(),r.end());
ll ndl=(SZ(l)?l[0]:-1),ndr=(SZ(r)?r[0]:-1);
if(SZ(r))r.erase(r.begin());
if(SZ(l))l.erase(l.begin());
if(ndl!=-1)build(ndl,nl,l);
if(ndr!=-1)build(ndr,nr,r);
if(SZ(line))build(nl,id,midl),build(id,nr,midr);
return ;
}
void Solve(ll n){
srand(clock());
vector<ll> v;
for(int i=2;i<n;i++)v.pb(i);
build(0,1,v);
for(auto i:ed){
if(i.X>i.Y)swap(i.X,i.Y);
Bridge(i.X,i.Y);
}
}
/*
int main(){
ll n;
cin>>n;
Solve(n);
return 0;
}
int Query(ll a,ll b,ll c){
cout<<"Q:"<<a<<" "<<b<<" "<<c<<"\n";
ll y;
cin>>y;
return y;
}
void Bridge(ll a,ll b){
cout<<a<<" "<<b<<"\n";
}
*/
Compilation message
meetings.cpp: In function 'void build(ll, ll, std::vector<int>)':
meetings.cpp:33:8: error: 'Query' was not declared in this scope
33 | ll x=Query(nl,nr,i);
| ^~~~~
meetings.cpp:52:8: error: 'Query' was not declared in this scope
52 | ll x=Query(nl,id,i);
| ^~~~~
meetings.cpp: In function 'void Solve(ll)':
meetings.cpp:78:3: error: 'Bridge' was not declared in this scope
78 | Bridge(i.X,i.Y);
| ^~~~~~
