Submission #486381

#	Time	Username	Problem	Language	Result	Execution time	Memory
486381		rainboy	Žarulje (COI15_zarulje)	C11	60 / 100	1090 ms	5328 KiB

zarulje

#include <stdio.h>

#define N	200000
#define MD	1000000007

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

unsigned int X = 12345;

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

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 (long long) ff[n] * gg[k] % MD * gg[n - k] % MD;
}

int aa[N];

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

		while (j < k) {
			int c = aa[ii[j]] != aa[i_] ? aa[ii[j]] - aa[i_] : ii[j] - i_;

			if (c == 0)
				j++;
			else if (c < 0) {
				tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
			}
		}
		sort(ii, l, i);
		l = k;
	}
}

int main() {
	static int ii[N];
	int n, k, h, i, j;

	init();
	scanf("%d%d", &n, &k);
	for (i = 0; i < n; i++) {
		scanf("%d", &aa[i]);
		ii[i] = i;
	}
	sort(ii, 0, n);
	while (k--) {
		int l, r, c, ans;

		scanf("%d", &c), c--;
		l = 0, r = n - 1, ans = 1;
		for (i = 0; i < n; i = j) {
			int l_, r_, kl, kr;

			j = i + 1;
			while (j < n && aa[ii[j]] == aa[ii[i]])
				j++;
			l_ = l, r_ = r, kl = kr = 0;
			for (h = i; h < j; h++) {
				if (ii[h] == c || ii[h] < l || ii[h] > r)
					continue;
				if (ii[h] < c)
					l_ = max(l_, ii[h] + 1), kl++;
				if (ii[h] > c)
					r_ = min(r_, ii[h] - 1), kr++;
			}
			ans = (long long) ans * choose(kl + kr, kl) % MD;
			l = l_, r = r_;
		}
		printf("%d\n", ans);
	}
	return 0;
}

Compilation message (stderr)

zarulje.c: In function 'main':
zarulje.c:61:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |  scanf("%d%d", &n, &k);
      |  ^~~~~~~~~~~~~~~~~~~~~
zarulje.c:63:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |   scanf("%d", &aa[i]);
      |   ^~~~~~~~~~~~~~~~~~~
zarulje.c:70:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |   scanf("%d", &c), c--;
      |   ^~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 38 / 38
• Subtask 3: 0 / 40