Submission #645393

#	Time	Username	Problem	Language	Result	Execution time	Memory
645393		gun_gan	Aliens (IOI07_aliens)	C++17	0 / 100	2 ms	364 KiB

aliens

#include <bits/stdc++.h>
using namespace std;

int n, x, y;

bool ask(int x, int y) {
	if(x <= 0 || y <= 0 || x > n || y > n) return 0;
	cout << "examine " << x << " " << y << endl;
	string s; cin >> s;
	return s == "true";
}

int main() {
	cin.tie(0); ios_base::sync_with_stdio(0);

	cin >> n >> x >> y;

	long long x1, x2, y1, y2;
	{
		int l = 0, r = n / 2;
		while(l <= r) {
			int mid = (l + r) / 2;
			if(ask(x, y + 2 * mid)) {
				l = mid + 1, y2 = mid;
			} else {
				r = mid - 1;
			}
		}
	}
	{
		int l = 0, r = n / 2;
		while(l <= r) {
			int mid = (l + r) / 2;
			if(ask(x, y - 2 * mid)) {
				l = mid + 1, y1 = mid;
			} else {
				r = mid - 1;
			}
		}
	}
	{
		int l = 0, r = n / 2;
		while(l <= r) {
			int mid = (l + r) / 2;
			if(ask(x - 2 * mid, y)) {
				l = mid + 1, x1 = mid;
			} else {
				r = mid - 1;
			}
		}
	}
	{
		int l = 0, r = n / 2;
		while(l <= r) {
			int mid = (l + r) / 2;
			if(ask(x + 2 * mid, y)) {
				l = mid + 1, x2 = mid;
			} else {
				r = mid - 1;
			}
		}
	}
	x1 = x - 2 * x1;
	x2 = x + 2 * x2;
	y1 = y - 2 * y1;
	y2 = y + 2 * y2;

	cout << "solution " << (x1 + x2) / 2 << " " << (y1 + y2) / 2 << endl;
}

Compilation message (stderr)

aliens.cpp: In function 'int main()':
aliens.cpp:66:13: warning: 'y2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   66 |  y2 = y + 2 * y2;
      |           ~~^~~~
aliens.cpp:65:13: warning: 'y1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   65 |  y1 = y - 2 * y1;
      |           ~~^~~~
aliens.cpp:63:13: warning: 'x1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   63 |  x1 = x - 2 * x1;
      |           ~~^~~~
aliens.cpp:64:13: warning: 'x2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   64 |  x2 = x + 2 * x2;
      |           ~~^~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10