Submission #718215

#	Time	Username	Problem	Language	Result	Execution time	Memory
718215		Tigerpants	Colors (BOI20_colors)	C++17	0 / 100	0 ms	208 KiB

Colors

#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <map>
#include <functional>
#include <numeric>

using namespace std;

typedef long long int ll;
typedef vector<ll> vll;

ll logll(ll x) {
    for (ll logx = 0; ; (x >>= 1) && (logx++)) if (x == 0) return logx;
}

bool ask(ll p) {
    cout << "? " << p << endl;
    bool answ;
    cin >> answ;
    return answ;
}

ll N;
ll lower = 0;
ll upper;

ll P;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> N;
    upper = 2 << logll(N - 1);

    P = (N + 2) / 3;

    ask(P);

    while ((lower + 1 < upper) && (lower < N - 1)) {
        ll mid = (upper + lower) / 2;
        if (2 * P > N) P -= mid;
        else P += mid;
        if (ask(P)) {
            upper = mid;
        } else {
            lower = mid;
        }
    }

    cout << "= " << min<ll>(N, upper) << endl;

    return 0;
}

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