Submission #827506

#	Time	Username	Problem	Language	Result	Execution time	Memory
827506		rainboy	Sum Zero (RMI20_sumzero)	C11	61 / 100	598 ms	42940 KiB

sumzero

#include <stdio.h>

#define N	400000
#define L	18	/* L = floor(log2(N + 1)) */

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

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) {
			int c = aa[ii[j]] != aa[i_] ? (aa[ii[j]] < aa[i_] ? -1 : 1) : 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 + 1], jj[L + 1][N + 2];
	int n, q, i, j, l, k;

	scanf("%d", &n);
	for (i = 1; i <= n; i++)
		scanf("%lld", &aa[i]), aa[i] += aa[i - 1];
	for (i = 0; i <= n; i++)
		ii[i] = i;
	sort(ii, 0, n + 1);
	jj[0][n + 1] = n + 1;
	for (i = 0; i <= n; i++)
		jj[0][ii[i]] = i == n || aa[ii[i + 1]] != aa[ii[i]] ? n + 1 : ii[i + 1];
	for (i = n; i >= 0; i--)
		jj[0][i] = min(jj[0][i], jj[0][i + 1]);
	for (l = 0; l < L; l++)
		for (i = 0; i <= n + 1; i++)
			jj[l + 1][i] = jj[l][jj[l][i]];
	scanf("%d", &q);
	while (q--) {
		scanf("%d%d", &i, &j), i--;
		k = 0;
		for (l = L; l >= 0; l--)
			if (jj[l][i] <= j)
				k += 1 << l, i = jj[l][i];
		printf("%d\n", k);
	}
	return 0;
}

Compilation message (stderr)

sumzero.c: In function 'main':
sumzero.c:42:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
sumzero.c:44:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |   scanf("%lld", &aa[i]), aa[i] += aa[i - 1];
      |   ^~~~~~~~~~~~~~~~~~~~~
sumzero.c:56:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |  scanf("%d", &q);
      |  ^~~~~~~~~~~~~~~
sumzero.c:58:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |   scanf("%d%d", &i, &j), i--;
      |   ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 39 / 39
• Subtask 3: 0 / 39