Submission #533096

#	Time	Username	Problem	Language	Result	Execution time	Memory
533096		kabika	Colors (BOI20_colors)	C++17	0 / 100	1 ms	200 KiB

Colors

#include <iostream>
#include <vector>
#include <algorithm>
#include <math.h>
using namespace std;
typedef long long ll;
constexpr ll INF = 1e18;

int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	ll n;
	cin >> n;
	vector<bool> vis(n + 1, 0);
	cout << "? 1\n";
	vis[1] = 1;
	bool resp;
	cin >> resp;
	bool flag = 1;
	ll l = 1, u = n;
	ll diff = (l + u) / 2;
	ll qr = l + diff;
	while (l < u)
	{
		cout << "? " << qr << endl;
		vis[qr] = 1;
		cin >> resp;
		if (resp)
		{
			u = diff;
		}
		else
		{
			l = diff + 1;
		}
		diff = (l + u) / 2;
		if (qr - diff >= 1 && !vis[qr - diff])
		{
			qr -= diff;
			continue;
		}
		if (qr + diff <= n && !vis[qr + diff])
		{
			qr += diff;
			continue;
		}
		break;
	}
	cout << "= " << l << endl;
	return 0;
}

Compilation message (stderr)

Colors.cpp: In function 'int main()':
Colors.cpp:21:7: warning: unused variable 'flag' [-Wunused-variable]
   21 |  bool flag = 1;
      |       ^~~~

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