Submission #768174

#	Time	Username	Problem	Language	Result	Execution time	Memory
768174		rainboy	Money (IZhO17_money)	C11	100 / 100	380 ms	22692 KiB

money

#include <stdio.h>

#define N	1000000
#define N_	(1 << 20)	/* N_ = pow2(ceil(log2(N + 1))) */

unsigned int Z = 12345;

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

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)
			if (aa[ii[j]] == aa[i_])
				j++;
			else if (aa[ii[j]] < aa[i_]) {
				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 st[N_ * 2], n_;

void pul(int i) {
	st[i] = st[i << 1 | 0] + st[i << 1 | 1];
}

void update(int i, int x) {
	st[i += n_] += x;
	while (i > 1)
		pul(i >>= 1);
}

int query(int r) {
	int l = 0;

	for (l += n_, r += n_; l <= r; l >>= 1, r >>= 1)
		if ((r & 1) == 0) {
			if (st[r] > 0) {
				while (r < n_)
					r = st[r << 1 | 1] > 0 ? r << 1 | 1 : r << 1 | 0;
				return r - n_;
			}
			r--;
		}
	return -1;
}

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

	scanf("%d", &n);
	for (i = 0; i < n; i++) {
		scanf("%d", &aa[i]);
		ii[i] = i;
	}
	sort(ii, 0, n);
	for (i = 0, a = 0; i < n; i++)
		aa[ii[i]] = i + 1 == n || aa[ii[i + 1]] != aa[ii[i]] ? a++ : a;
	n_ = 1;
	while (n_ <= n)
		n_ <<= 1;
	for (i = 0; i < n; i++)
		update(aa[i], 1);
	k = 0;
	for (j = n - 1; j >= 0; j = i) {
		i = j - 1;
		while (i >= 0 && aa[i] == aa[j])
			i--;
		update(aa[j], -(j - i));
		a = aa[j] - 1;
		while (i >= 0 && aa[i] == query(a))
			update(aa[i], -1), a = aa[i], i--;
		k++;
	}
	printf("%d\n", k);
	return 0;
}

Compilation message (stderr)

money.c: In function 'main':
money.c:64:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
money.c:66:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |   scanf("%d", &aa[i]);
      |   ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 20 / 20
• Subtask 4: 55 / 55