Submission #992677

#	Time	Username	Problem	Language	Result	Execution time	Memory
992677		amin_2008	Guess the number (BOI20_guess)	C++17	100 / 100	1 ms	596 KiB

Guess

#include "bits/stdc++.h"

using namespace std;

#define int long long

const int sz = 2e5 + 5;
const int inf = 1e18;

void solve()
{
    int n;
    cin >> n;
    auto ask = [&](int x) 
    {
        cout << "? " << x << endl;
        cout.flush();
        int a;
        cin >> a;
        return a;
    };
    int l = 0, r = n + 1;
    while (r - l > 1) 
    {
        int mid = (l + r) >> 1;
        int x = ask(mid);
        if (!x) 
        {
            cout << "= " << mid << endl;
            return;
        }
        else if (x == -1) l = mid;
        else r = mid;
    }
}

signed main() 
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int t = 1;
    // cin >> t;
    for(int i = 1; i <= t; i++) solve();
}

• Subtask 1: 29 / 29
• Subtask 2: 71 / 71