Submission #395151

#	Time	Username	Problem	Language	Result	Execution time	Memory
395151		rainboy	Vudu (COCI15_vudu)	C11	140 / 140	357 ms	25560 KiB

vudu

#include <stdio.h>

#define N	1000000

unsigned int X = 12345;

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

long long aa[N + 1];

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) {
			long long 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 ft[N + 1];

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

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

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

int main() {
	static int ii[N + 1];
	int n, i, a;
	long long ans;

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

Compilation message (stderr)

vudu.c: In function 'main':
vudu.c:59:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   59 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
vudu.c:61:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   61 |   scanf("%lld", &aa[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~
vudu.c:62:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   62 |  scanf("%d", &a);
      |  ^~~~~~~~~~~~~~~

• Subtask 1: 140 / 140