Submission #1131612

#	Time	Username	Problem	Language	Result	Execution time	Memory
1131612		alterio	Colors (BOI20_colors)	C++20	0 / 100	0 ms	416 KiB

Colors

#include <bits/stdc++.h>

using namespace std;

#define endl '\n'
#define ll long long
#define all(x) (x).begin(), (x).end()

int ask(int x) {
    cout << "? " << x << endl;
    int val;
    cin >> val;
    return val;
}

int main() {
    int n;
    cin >> n;
    int l = 0, r = n;
    int pos = (n + 1) / 2 - (n / 4) + (n % 2 == 0); 
    ask(pos);
    unordered_set<int> used;
    while (l + 1 < r) {
        int mid = (l + r) / 2;
        if (pos + mid <= n && !used.count(pos + mid)) pos += mid;
        else pos -= mid;
        used.insert(pos);
        int x = ask(pos);
        if (x) r = mid;
        else l = mid;
    }
    cout << "= " << r << endl;
}

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