Submission #875861

#	Time	Username	Problem	Language	Result	Execution time	Memory
875861		rainboy	Rabbit Carrot (LMIO19_triusis)	C11	100 / 100	70 ms	2732 KiB

triusis

#include <stdio.h>

#define N	200000

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

unsigned int X = 12345;

int rand_() {
	return (X *= 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) {
			int c = aa[ii[j]] != aa[i_] ? aa[ii[j]] - aa[i_] : i_ - ii[j];

			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 ft[N];

void update(int i, int n, int x) {
	while (i < n) {
		ft[i] = max(ft[i], x);
		i |= i + 1;
	}
}

int query(int i) {
	int x = 0;

	while (i >= 0) {
		x = max(x, ft[i]);
		i &= i + 1, i--;
	}
	return x;
}

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

	scanf("%d%d", &n, &d);
	for (i = 0; i < n; i++) {
		scanf("%d", &aa[i]), aa[i] -= d * (i + 1);
		ii[i] = i;
	}
	sort(ii, 0, n);
	for (h = 0; h < n && aa[i = ii[h]] <= 0; h++)
		update(n - 1 - i, n, query(n - 1 - i) + 1);
	printf("%d\n", n - query(n - 1));
	return 0;
}

Compilation message (stderr)

triusis.c: In function 'main':
triusis.c:60:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |  scanf("%d%d", &n, &d);
      |  ^~~~~~~~~~~~~~~~~~~~~
triusis.c:62:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |   scanf("%d", &aa[i]), aa[i] -= d * (i + 1);
      |   ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 21 / 21
• Subtask 3: 28 / 28
• Subtask 4: 37 / 37