Submission #1086002

#	Time	Username	Problem	Language	Result	Execution time	Memory
1086002		not_amir	Colors (BOI20_colors)	C++14	100 / 100	1 ms	600 KiB

Colors

#include <bits/stdc++.h>
using namespace std;

#define T

typedef long long ll;

int ask(ll q){
    static ll bef = 0;
    cout << "? " << q << endl;
    int ans;
    cin >> ans;
    return ans;
}

ll solve(ll n, ll c, ll add, bool dir){
    if(n == 1)
        return 1 + add;
    ll diff = n/2 + add;
    ll q = dir?c+diff:c-diff;
    if(ask(q))
        return solve(n/2, q, add, !dir);
    else
        return solve((n+1)/2, q, add + n/2, !dir);
}

ll start(ll n){
    if(n == 2)
        return 1;
    return  (n + 1)/2  + 1 - start((n + 1)/2);
}

int main(){
//   ios_base::sync_with_stdio(false);
//   cin.tie(NULL);
    ll n;
    cin >> n;
    ll c = start(n);
    ask(c);
    ll ans = solve(n, c, 0, 1);
    cout << "= " << ans;
}

Compilation message (stderr)

Colors.cpp: In function 'int ask(ll)':
Colors.cpp:9:15: warning: unused variable 'bef' [-Wunused-variable]
    9 |     static ll bef = 0;
      |               ^~~
Colors.cpp: At global scope:
Colors.cpp:9:15: warning: 'bef' defined but not used [-Wunused-variable]

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