Language: C++

#include <iostream>
#include <iomanip>
#include <string>
#include <stack>
#include <vector>
#include <math.h>
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <map>
#include <set>
#include <queue>
#include <list>
#include <regex>
using namespace std;
using pii  = pair<int,int>;
using ll=long long;
using ld=long double;
#define pb push_back
#define mp make_pair
#define sc second
#define fr first
#define stpr setprecision
#define cYES cout<<"YES"<<endl
#define cNO cout<<"NO"<<endl
#define cYes cout<<"Yes"<<endl
#define cNo cout<<"No"<<endl
#define rep(i,n) for(ll i=0;i<(n);++i)
#define Rep(i,a,b) for(ll i=(a);i<(b);++i)
#define rrep(i,n) for(int i=n-1;i>=0;i--)
#define rRep(i,a,b) for(int i=a;i>=b;i--)
#define crep(i) for(char i='a';i<='z';++i)
#define psortsecond(A,N) sort(A,A+N,[](const pii &a, const pii &b){return a.second<b.second;});
#define ALL(x) (x).begin(),(x).end()
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define endl '\n'
int ctoi(const char c){
  if('0' <= c && c <= '9') return (c-'0');
  return -1;
}
ll gcd(ll a,ll b){return (b == 0 ? a : gcd(b, a%b));}
ll lcm(ll a,ll b){return a*b/gcd(a,b);}
constexpr ll MOD=1000000007;
constexpr ll INF=1000000011;
constexpr ll MOD2=998244353;
constexpr ll LINF = 1001002003004005006ll;
constexpr ld EPS=10e-8;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template<typename T> istream& operator>>(istream& is,vector<T>& v){for(auto&& x:v)is >> x;return is;}
template<typename T,typename U> istream& operator>>(istream& is, pair<T,U>& p){ is >> p.first; is >> p.second; return is;}
template<typename T,typename U> ostream& operator>>(ostream& os, const pair<T,U>& p){ os << p.first << ' ' << p.second; return os;}
template<class T> ostream& operator<<(ostream& os, vector<T>& v){
    for(auto i=begin(v); i != end(v); ++i){
        if(i !=begin(v)) os << ' ';
        os << *i;
    }
    return os;
}

int main(){
    ll N,ans[200],C;
    cin >> N;
    string S,T,G;
    rep(i,N){
        ans[i] = 0;
    }
    cout << "?" << " ";
    rep(i,N){
        cout << i << " ";
    }
    T.clear();
    cin >> T;
    ll ng=N,ok=0;
    while(ng-ok>1){
        ll mid = (ok+ng)/2;
        cout << "?" << " ";
        Rep(i,mid,mid+N){
            cout << i << " ";
            if(i!=mid+N-1){
                cout << " ";
            }
        }
        cin >> T;
        if(S==T){
            ok = mid;
        }
        else{
            ng = mid;
        }
    }
    ok = ok + 1;
    rep(i,2*N){
      cout << "?" << " ";  
      if(i>=ok && i<ok+N-2){
          key=ok+N;
      }
      else{
          key=ok;
      }
      rep(j,N-1){
          cout << (j+key)%(2*N) << " ";
      }
      cout << i << endl;
      cin >> T ;
      if(T[0]=='R') {
          ans[i]=0;
      }
      else{
          ans[i]=1;
      }
    }
    cout << "!";
    rep(i,2*N){
        cout << (ans[i]==0 ? 'R' : 'B') ;
        if(i!=2*N-1){
            cout << " ";
        }
    }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:97:11: error: 'key' was not declared in this scope; did you mean 'key_t'?
   97 |           key=ok+N;
      |           ^~~
      |           key_t
a.cc:100:11: error: 'key' was not declared in this scope; did you mean 'key_t'?
  100 |           key=ok;
      |           ^~~
      |           key_t
a.cc:103:22: error: 'key' was not declared in this scope; did you mean 'key_t'?
  103 |           cout << (j+key)%(2*N) << " ";
      |                      ^~~
      |                      key_t