Submission #823946

#	Time	Username	Problem	Language	Result	Execution time	Memory
823946		rainboy	Triangle Collection (CCO23_day2problem3)	C11	25 / 25	192 ms	16680 KiB

Main

#include <stdio.h>

#define N	200000
#define N_	(1 << 18)	/* N_ = pow2(ceil(log2(N))) */

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

long long ss[N_ * 2], qq[N_ * 2]; int n_;

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

	ss[i] = ss[l] + ss[r];
	qq[i] = min(qq[l] + ss[r], qq[r]);
}

void build(int *aa, int n) {
	int i;

	n_ = 1;
	while (n_ < n)
		n_ <<= 1;
	for (i = 0; i < n; i++) {
		ss[n_ + i] += aa[i] / 2;
		if (aa[i] % 2 != 0)
			ss[n_ + (i + 1) / 2]--;
	}
	for (i = 0; i < n_; i++)
		qq[n_ + i] = min(ss[n_ + i], 0);
	for (i = n_ - 1; i > 0; i--)
		pul(i);
}

void update(int i, int x) {
	i += n_;
	qq[i] = min(ss[i] += x, 0);
	while (i > 1)
		pul(i >>= 1);
}

int main() {
	static int aa[N];
	int n, q, i, d;
	long long sum;

	scanf("%d%d", &n, &q);
	sum = 0;
	for (i = 0; i < n; i++) {
		scanf("%d", &aa[i]);
		sum += aa[i];
	}
	build(aa, n);
	while (q--) {
		scanf("%d%d", &i, &d), i--;
		update(i, -(aa[i] / 2));
		if (aa[i] % 2 != 0)
			update((i + 1) / 2, 1);
		aa[i] += d, sum += d;
		update(i, aa[i] / 2);
		if (aa[i] % 2 != 0)
			update((i + 1) / 2, -1);
		printf("%lld\n", (sum + qq[1]) / 3);
	}
	return 0;
}

Compilation message (stderr)

Main.c: In function 'main':
Main.c:46:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |  scanf("%d%d", &n, &q);
      |  ^~~~~~~~~~~~~~~~~~~~~
Main.c:49:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |   scanf("%d", &aa[i]);
      |   ^~~~~~~~~~~~~~~~~~~
Main.c:54:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |   scanf("%d%d", &i, &d), i--;
      |   ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5