Submission #341925

#	Time	Username	Problem	Language	Result	Execution time	Memory
341925		a_player	Colors (BOI20_colors)	C++14	0 / 100	1 ms	364 KiB

Colors

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

int query(ll a){
  cout<<"? "<<a<<endl;
  int b;
 cin>>b;
 return b;
}
void answer(ll a){
  cout<<"= "<<a<<endl;
  exit(0);
}

int main(){
  int N;
  cin>>N;
  int ans=query(N/2);
  ans=query(1);
  if(ans==1){
    ans=query(N/2-1);
    if(ans==0)answer(N/2-1);
    int last=N/2-2;
    for(int i=2,j=N/2-2;last>1;i++,j--){
      ans=query(i);
      if(ans==0)answer(last);
      last--;
      if(last<=1)break;
      ans=query(j);
      if(ans==0)answer(last);
      last--;
    }
    answer(1);
  }
  else{
    ans=query(N);
    if(ans==0)answer(N);
    int last=N-1;
    for(int i=2,j=N-1;last>N/2;i++,j--){
      ans=query(i);
      if(ans==0)answer(last);
      last--;
      if(last<=N/2)break;
      ans=query(j);
      if(ans==0)answer(last);
      last--;
    }
    answer(N/2);
  }
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 13
• Subtask 3: 0 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 33