Submission #649651

#	Time	Username	Problem	Language	Result	Execution time	Memory
649651		DJeniUp	Colors (BOI20_colors)	C++17	0 / 100	1 ms	208 KiB

Colors

#include "bits/stdc++.h"
//#pragma GCC optimize("O3")

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll>pairll;
typedef long double ld;

#define fr first
#define sc second
#define pb push_back
#define INF 100000000007
#define endl '\n'
#define MOD 998244353
#define A 31
#define N 500007

ll n;

int main(){
    
    cin>>n;
    if(n==1){
        cout<<"= "<<1<<endl;
        cout.flush();
        return 0;
    }
    ll a=1;
    ll b=1+n/3;
    ll c=n-(n-1)/3;
    ll d=n;
    ll f=0;
    ll f1=-1;
    cout<<"? "<<b<<endl;
    cout.flush();
    ll x;
    cin>>x;
    
    while(1){
        //cout<<a<<" "<<b<<" "<<c<<" "<<d<<endl;
        if(a==b && c==d){
            cout<<"= "<<d-a<<endl;
            cout.flush();
            return 0;
        }
        if(f==-1){
            f=0;
            cout<<"? "<<b<<endl;
            cout.flush();
            cin>>x;
            if(x==0){
                if(b==a && c==d){
                    cout<<"= "<<d-a+1<<endl;
                    cout.flush();
                    return 0;
                }else{
                    f1=-1;
                    c=(d+c+1)/2;
                }
            }else{
                d=c-1;
                f1=-1;
                c=(b+d+1)/2;
            }
        }else{
            f1=0;
            cout<<"? "<<c<<endl;
            cout.flush();
            cin>>x;
            if(x==0){
                if(b==a && c==d){
                    cout<<"= "<<d-a+1<<endl;
                    cout.flush();
                    return 0;
                }else{
                    f=-1;
                    b=(a+b)/2;
                }
            }else{
                f=-1;
                a=b+1;
                b=(a+c)/2;
            }
        }
    }
    
    return 0;
}

Compilation message (stderr)

Colors.cpp: In function 'int main()':
Colors.cpp:35:8: warning: variable 'f1' set but not used [-Wunused-but-set-variable]
   35 |     ll f1=-1;
      |        ^~

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