Submission #493279

#	Time	Username	Problem	Language	Result	Execution time	Memory
493279		rainboy	Cigle (COI21_cigle)	C11	48 / 100	1091 ms	46540 KiB

cigle

#include <stdio.h>
#include <string.h>

#define N	5000
#define N_	(1 << 13)

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

int ss[N_ * 2], pp[N_ * 2], n_;

void pul(int i) {
	int l = i << 1, r = l | 1;

	ss[i] = ss[l] + ss[r];
	pp[i] = max(pp[l], ss[l] + pp[r]);
}

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

int main() {
	static int aa[N + 1], dp[N + 1][N + 1];
	int n, i, j, k, ans;

	scanf("%d", &n);
	for (i = 1; i <= n; i++) {
		scanf("%d", &aa[i]);
		aa[i] += aa[i - 1];
	}
	for (i = 1; i <= n; i++)
		dp[0][i] = 0;
	n_ = 1;
	while (n_ < n)
		n_ <<= 1;
	for (j = 1; j <= n; j++) {
		memset(ss, 0, n_ * 2 * sizeof *ss);
		for (i = 0; i < j; i++) {
			update(i, dp[i][j]);
			if (i + 1 < n)
				update(i + 1, -dp[i][j]);
		}
		for (k = j + 1, i = j - 1; k <= n; k++) {
			dp[j][k] = pp[1];
			while (i >= 0 && aa[i] + aa[k] > aa[j] * 2)
				i--;
			if (i >= 0 && aa[i] + aa[k] == aa[j] * 2)
				update(0, 1), update(i, -1);
		}
	}
	ans = 0;
	for (i = 0; i < n; i++)
		ans = max(ans, dp[i][n]);
	printf("%d\n", ans);
	return 0;
}

Compilation message (stderr)

cigle.c: In function 'main':
cigle.c:29:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
cigle.c:31:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |   scanf("%d", &aa[i]);
      |   ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 0 / 52