Submission #1056315

#	Time	Username	Problem	Language	Result	Execution time	Memory
1056315		rainboy	Bring Down the Grading Server (CEOI23_gradingserver)	C11	10 / 100	72 ms	1228 KiB

gradingserver

#include <stdio.h>

long long min(long long a, long long b) { return a < b ? a : b; }
long long max(long long a, long long b) { return a > b ? a : b; }

int c;

int solve(long long x1, long long y1, long long x2, long long y2) {
	long long y;

	if (x1 + y1 * c <= 0)
		return 0;
	if (x2 + y2 * c <= 0)
		return 1;
	if (x1 <= 0) {
		if (x2 > 0) {
			if (x2 >= c)
				return 0;
			if (y2 > 0) {
				if (x2 - x1 >= c)
					return 0;
				return !solve(x2, y2, x1 + c, y1 - 1);
			}
			y = -x1 / (c - x2) + 1;
			return y <= y1 && solve(x1 + y * (c - x2), y1 - y, x2, y2);
		} else {
			y = min(-x1 / c + 1, -x2 / c + 1);
			return solve(x1 + y * c, y1 - y, x2 + y * c, y2 - y);
		}
	}
	if (x1 >= x2 && (x1 >= c || y1 > 0))
		return 1;
	if (x2 < c && x1 + y1 * (c - x2) >= c)
		return 1;
	if (!solve(x2 - x1, y2, x1, y1))
		return 1;
	if (x2 >= c || y2 >= c)
		return 0;
	y = y2 == 0 ? 1 : max((x2 + c * (y2 - 1)) / (y2 + 1) + 1 - x1, 0) / (c - x2) + 1;
	return y <= y1 && solve(x1 + y * (c - x2), y1 - y, x2, y2);
}

int main() {
	int t;

	scanf("%d%d", &c, &t);
	while (t--) {
		long long x1, y1, x2, y2;

		scanf("%lld%lld%lld%lld", &x1, &y2, &x2, &y1), x1 -= y1 * c, x2 -= y2 * c;
		printf(solve(x1, y1, x2, y2) ? "YES\n" : "NO\n");
	}
	return 0;
}

Compilation message (stderr)

gradingserver.c: In function 'main':
gradingserver.c:46:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |  scanf("%d%d", &c, &t);
      |  ^~~~~~~~~~~~~~~~~~~~~
gradingserver.c:50:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |   scanf("%lld%lld%lld%lld", &x1, &y2, &x2, &y1), x1 -= y1 * c, x2 -= y2 * c;
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 10 / 10
• Subtask 5: 0 / 25
• Subtask 4: 0 / 20
• Subtask 6: 0 / 20
• Subtask 7: 0 / 15