Submission #823177

#	Time	Username	Problem	Language	Result	Execution time	Memory
823177		rainboy	Binaria (CCO23_day1problem1)	C11	25 / 25	103 ms	15916 KiB

Main

#include <stdio.h>

#define N	1000000
#define MD	1000003

int vv[N + 1], ff[N + 1], gg[N + 1];

void init() {
	int i;

	ff[0] = gg[0] = 1;
	for (i = 1; i <= N; i++) {
		vv[i] = i == 1 ? 1 : (long long) vv[i - MD % i] * (MD / i + 1) % MD;
		ff[i] = (long long) ff[i - 1] * i % MD;
		gg[i] = (long long) gg[i - 1] * vv[i] % MD;
	}
}

int choose(int n, int k) {
	return k < 0 || k > n ? 0 : (long long) ff[n] * gg[k] % MD * gg[n - k] % MD;
}

int main() {
	static int kk[N];
	int n, k, i, r, a, k1, k01;

	init();
	scanf("%d%d", &n, &k);
	for (i = 0; i + k <= n; i++)
		scanf("%d", &kk[i]);
	k01 = k1 = 0;
	for (r = 0; r < k; r++) {
		a = -1;
		for (i = r; i + k < n; i += k)
			if (kk[i + 1] != kk[i]) {
				if (kk[i + 1] - kk[i] == 1)
					a = 0;
				else if (kk[i + 1] - kk[i] == -1)
					a = 1;
				else
					a = -2;
				break;
			}
		if (a == -2) {
			printf("0\n");
			return 0;
		}
		if (a == -1) {
			k01++;
			continue;
		}
		if (a == 1)
			k1++;
		for (i = r; i + k < n; i += k) {
			a += kk[i + 1] - kk[i];
			if (a != 0 && a != 1) {
				printf("0\n");
				return 0;
			}
		}
	}
	printf("%d\n", choose(k01, kk[0] - k1));
	return 0;
}

Compilation message (stderr)

Main.c: In function 'main':
Main.c:28:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |  scanf("%d%d", &n, &k);
      |  ^~~~~~~~~~~~~~~~~~~~~
Main.c:30:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |   scanf("%d", &kk[i]);
      |   ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 3 / 3
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
• Subtask 6: 7 / 7