Submission #370965

#	Time	Username	Problem	Language	Result	Execution time	Memory
370965		flappybird	Colors (BOI20_colors)	C++14	0 / 100	1 ms	364 KiB

Colors

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MAX 101010
#define ln '\n'
#define bb ' '
#define abs(x) ((x)>0?(x):-(x))
ll query(ll x) {
	cout << '?' << bb << x << endl;
	ll ret;
	cin >> ret;
	return ret;
}
signed main() {
	ll N;
	cin >> N;
	ll l, r, mid;
	l = 0, r = N;
	ll prev = N / 2;
	query(prev);
	ll res;
	while (r - l > 1) {
		mid = (l + r + 1) >> 1;
		if (1 <= prev + mid && prev + mid <= N && 1 <= prev - mid && prev - mid <= N) {
			ll a = min(abs(prev + mid - 1), abs(prev + mid - N));
			ll b = min(abs(prev - mid - 1), abs(prev - mid - N));
			if (a < b) {
				prev += mid;
				res = query(prev);
			}
			else {
				prev -= mid;
				res = query(prev);
			}
		}
		else if (1 <= prev + mid && prev + mid <= N) {
			prev += mid;
			res = query(prev);
		}
		else if (1 <= prev - mid && prev - mid <= N) {
			prev -= mid;
			res = query(prev);
		}
		else {
			query(1);
			res = query(mid + 1);
		}
		if (res) r = mid;
		else l = mid;
	}
	cout << '=' << bb << r << endl;
}

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