Submission #649647

#	Time	Username	Problem	Language	Result	Execution time	Memory
649647		welleyth	Colors (BOI20_colors)	C++17	0 / 100	1 ms	300 KiB

Colors

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define int long long
#define pb push_back
#define mp make_pair

//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

constexpr int N = (int)2e5 + 111;
constexpr int md = (int)2e5 + 111;

mt19937 rnd(time(nullptr));

set<int> was_asked;

int ask(int x){
    assert(!was_asked.count(x));
    was_asked.insert(x);
    cout << "? " << x << "\n";
    cout.flush();
    int answer;
    cin >> answer;
    return answer;
}

void solve(){
    int n;
    cin >> n;

    ask(1);
    int pr = 1;

    int l = 2, r = n;
    for(int it = 0; l <= r; it^=1){
        if(it == 0){
            int check = ask(r--);
            if(!check){
                cout << "= " << r - l + 3 << "\n";
                return;
            }
        } else {
            int check = ask(l++);
            if(!check){
                cout << "= " << r - l + 3 << "\n";
                return;
            }
        }
    }

    return;
}

signed main(){
    ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
//    init();
    int tests = 1;
//    cin >> tests;
    for(int test = 1; test <= tests; test++){
//        cerr << "test = " << test << "\n";
        solve();
    }
    return 0;
}
/**

**/

Compilation message (stderr)

Colors.cpp: In function 'void solve()':
Colors.cpp:37:9: warning: unused variable 'pr' [-Wunused-variable]
   37 |     int pr = 1;
      |         ^~

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