Submission #481178

#	Time	Username	Problem	Language	Result	Execution time	Memory
481178		rainboy	Drvca (COCI19_drvca)	C11	110 / 110	47 ms	3060 KiB

drvca

#include <stdio.h>
#include <string.h>

#define N	100000

unsigned int X = 12345;

int rand_() {
	return (X *= 3) >> 1;
}

void sort(int *aa, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r, a = aa[l + rand_() % (r - l)], tmp;

		while (j < k)
			if (aa[j] == a)
				j++;
			else if (aa[j] < a) {
				tmp = aa[i], aa[i] = aa[j], aa[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = aa[j], aa[j] = aa[k], aa[k] = tmp;
			}
		sort(aa, l, i);
		l = k;
	}
}

int solve(int *aa, int n, int a, int b) {
	static char in[N];
	static int dd[N];
	int i, k, c, d;

	memset(in, 0, n * sizeof *in);
	for (i = n - 2; i >= 0; i--)
		dd[i] = i == n - 2 || dd[i + 1] == aa[i + 1] - aa[i] ? aa[i + 1] - aa[i] : -2;
	k = 0, c = -1, d = -1;
	for (i = 0; i < n; i++)
		if (aa[i] == a) {
			in[i] = 1, a += b, k++;
			if (k < n) {
				if (i == n - 2) {
					if (c != -1 && d != -1 && aa[i + 1] - c != d)
						continue;
				} else if (i < n - 2) {
					if (dd[i + 1] == -2)
						continue;
					if (d != -1 && d != dd[i + 1])
						continue;
					if (c != -1 && aa[i + 1] - c != dd[i + 1])
						continue;
				}
				printf("%d\n", k);
				for (i = 0; i < n; i++)
					if (in[i])
						printf("%d ", aa[i]);
				printf("\n");
				printf("%d\n", n - k);
				for (i = 0; i < n; i++)
					if (!in[i])
						printf("%d ", aa[i]);
				printf("\n");
				return 1;
			}
		} else {
			if (c != -1) {
				if (d != -1 && aa[i] - c != d)
					return 0;
				d = aa[i] - c;
			}
			c = aa[i];
		}
	return 0;
}

int main() {
	static int aa[N];
	int n, i;

	scanf("%d", &n);
	for (i = 0; i < n; i++)
		scanf("%d", &aa[i]);
	sort(aa, 0, n);
	if (!solve(aa, n, aa[0], aa[1] - aa[0]) && !solve(aa, n, aa[0], aa[2] - aa[0]) && !solve(aa, n, aa[1], aa[2] - aa[1])) {
		printf("-1\n");
		return 0;
	}
	return 0;
}

Compilation message (stderr)

drvca.c: In function 'main':
drvca.c:82:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
drvca.c:84:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |   scanf("%d", &aa[i]);
      |   ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 30 / 30
• Subtask 4: 30 / 30