#include <bits/stdc++.h>
//#include "communication.h"
#pragma GCC optimize("Ofast")
#define AquA cin.tie(0);ios_base::sync_with_stdio(0);
#define fs first
#define sc second
#define p_q priority_queue
using namespace std;
const int B=32000;
vector<int> use(vector<int> a,vector<int> b,int x,int t){
vector<int> la,ra,lb,rb;
if(a.size()+b.size()<=3){
vector<int> g;
for(auto h:a){
g.push_back(h);
}
for(auto h:b){
g.push_back(h);
}
sort(g.begin(),g.end());
assert(g.size()==3);
int u=-1;
for(int i=0;i<3;i++){
if(g[i]==x){
u=i;
}
}
if(t==0){
if(u==-1){
return g;
}
return vector<int>(1,u);
}
else{
string s[3]={"1111","0001","1000"};
if(u==-1){
string z;
for(int j=0;j<4;j++){
z+=char('0'+receive());
}
int flag=-1;
for(int i=0;i<3;i++){
int lst=0;
for(int j=0;j<4;j++){
if(s[i][j]!=z[j]){
if(lst){
flag=1;
break;
}
else{
lst=1;
}
}
else{
lst=0;
}
}
}
assert(flag>=0);
vector<int> ret;
for(int i=0;i<3;i++){
if(i!=flag){
ret.push_back(g[i]);
}
}
return ret;
}
else{
for(int i=0;i<4;i++){
send(int(s[u][i]-'0'));
}
}
}
}
int as=a.size(),bs=b.size();
int nxt=-1;
for(int i=0;i<as/2;i++){
if(a[i]==x){
nxt=0;
}
la.push_back(a[i]);
rb.push_back(a[i]);
}
for(int i=as/2;i<as;i++){
if(a[i]==x){
nxt=1;
}
ra.push_back(a[i]);
lb.push_back(a[i]);
}
for(int i=0;i<(bs+1)/2;i++){
if(b[i]==x){
nxt=0;
}
la.push_back(b[i]);
}
for(int i=(bs+1)/2;i<bs;i++){
if(b[i]==x){
nxt=1;
}
ra.push_back(b[i]);
}
int dd;
if(nxt==-1){
dd=receive();
}
else{
dd=send(nxt);
}
if(dd==0){
use(la,lb,x,t);
}
else{
use(la,lb,x,t);
}
}
const int n=1e9;
void encode(int N,int x){
int a=x/B;
int c=x%B;
vector<int> v(n/B+1);
iota(v.begin(),v.end(),0);
auto e=use(v,vector<int>(),a,0);
vector<int> w(B);
iota(w.begin(),w.end(),0);
auto f=use(w,vector<int>(),c,0);
assert(e.size()==1 && f.size()==1);
vector<int> z(9);
iota(z.begin(),z.end(),0);
auto t=use(z,vector<int>(),3*e[0]+f[0],1);
assert(t.size()==0);
}
pair<int,int> decode(int n){
vector<int> v(n/B+1);
iota(v.begin(),v.end(),0);
auto e=use(v,vector<int>(),-1,0);
vector<int> w(B);
iota(w.begin(),w.end(),0);
auto f=use(w,vector<int>(),-1,0);
assert(e.size()==3 && f.size()==3);
vector<int> z;
for(auto h:e){
for(auto y:f){
z.push_back(h*B+y);
}
}
auto j=use(z,vector<int>(),-1,1);
assert(j.size()==2);
return {j[0],j[1]};
}
Compilation message
communication.cpp: In function 'std::vector<int> use(std::vector<int>, std::vector<int>, int, int)':
communication.cpp:40:33: error: 'receive' was not declared in this scope
40 | z+=char('0'+receive());
| ^~~~~~~
communication.cpp:71:21: error: 'send' was not declared in this scope
71 | send(int(s[u][i]-'0'));
| ^~~~
communication.cpp:106:12: error: 'receive' was not declared in this scope
106 | dd=receive();
| ^~~~~~~
communication.cpp:109:12: error: 'send' was not declared in this scope
109 | dd=send(nxt);
| ^~~~
communication.cpp:12:17: warning: control reaches end of non-void function [-Wreturn-type]
12 | vector<int> la,ra,lb,rb;
| ^~
