Submission #768770

#	Time	Username	Problem	Language	Result	Execution time	Memory
768770		rainboy	Chessboard (IZhO18_chessboard)	C11	100 / 100	290 ms	4228 KiB

chessboard

#include <stdio.h>

#define N	100000
#define INF	0x3f3f3f3f3f3f3f3fLL

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

int f(int s, int a) {
	a %= s * 2;
	return min(a, s * 2 - a);
}

int main() {
	static int xx1[N], yy1[N], xx2[N], yy2[N];
	int n, s, t, i;
	long long k, k_;

	scanf("%d%d", &s, &n);
	for (i = 0; i < n; i++)
		scanf("%d%d%d%d", &xx1[i], &yy1[i], &xx2[i], &yy2[i]), xx1[i]--, yy1[i]--;
	k_ = INF;
	for (t = 1; t < s; t++)
		if (s % t == 0) {
			k = (long long) (s / t) * (s / t) / 2 * t * t;
			for (i = 0; i < n; i++)
				k += (long long) (f(t, xx2[i]) - f(t, xx1[i])) * (f(t, yy2[i]) - f(t, yy1[i]));
			k_ = min(k_, min(k, (long long) s * s - k));
		}
	printf("%lld\n", k_);
	return 0;
}

Compilation message (stderr)

chessboard.c: In function 'main':
chessboard.c:18:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |  scanf("%d%d", &s, &n);
      |  ^~~~~~~~~~~~~~~~~~~~~
chessboard.c:20:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |   scanf("%d%d%d%d", &xx1[i], &yy1[i], &xx2[i], &yy2[i]), xx1[i]--, yy1[i]--;
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 23 / 23
• Subtask 6: 30 / 30