Submission #432575

#	Time	Username	Problem	Language	Result	Execution time	Memory
432575		rainboy	Hiring (IOI09_hiring)	C11	100 / 100	943 ms	15424 KiB

hiring

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

#define N	500000

unsigned int X = 12345;

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

int ss[N], qq[N];

int compare(int i, int j) { return ss[i] * qq[j] - ss[j] * qq[i]; }

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 = compare(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 pq[N], iq[1 + N], cnt;

int lt(int i, int j) { return qq[i] > qq[j]; }

int p2(int p) {
	return (p *= 2) > cnt ? 0 : (p < cnt && lt(iq[p + 1], iq[p]) ? p + 1 : p);
}

void pq_up(int i) {
	int p, q, j;

	for (p = pq[i]; (q = p / 2) && lt(i, j = iq[q]); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}

void pq_dn(int i) {
	int p, q, j;

	for (p = pq[i]; (q = p2(p)) && lt(j = iq[q], i); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}

void pq_add(int i) {
	pq[i] = ++cnt, pq_up(i);
}

int pq_remove_first() {
	int i = iq[1], j = iq[cnt--];

	if (j != i)
		pq[j] = 1, pq_dn(j);
	pq[i] = 0;
	return i;
}

int main() {
	static int ii[N];
	int n, i, cnt_;
	long long w, p, p_, q_;

	scanf("%d%lld", &n, &w);
	for (i = 0; i < n; i++) {
		scanf("%d%d", &ss[i], &qq[i]);
		ii[i] = i;
	}
	sort(ii, 0, n);
	cnt_ = -1, p_ = q_ = -1, p = 0;
	for (i = 0; i < n; i++) {
		int i_ = ii[i], s = ss[i_], q = qq[i_];

		pq_add(i_), p += qq[i_];
		while (cnt && p * s > w * q)
			p -= qq[pq_remove_first()];
		if (cnt_ < cnt || cnt_ == cnt && p_ * q > p * s * q_)
			cnt_ = cnt, p_ = p * s, q_ = q;
	}
	memset(pq, 0, n * sizeof *pq), cnt = 0;
	p = 0;
	for (i = 0; i < n; i++) {
		int i_ = ii[i], s = ss[i_], q = qq[i_];

		pq_add(i_), p += qq[i_];
		while (cnt && p * s > w * q)
			p -= qq[pq_remove_first()];
		if (cnt_ == cnt && p_ * q == p * s * q_) {
			printf("%d\n", cnt);
			for (i = 1; i <= cnt; i++)
				printf("%d\n", iq[i] + 1);
			return 0;
		}
	}
	return 0;
}

Compilation message (stderr)

hiring.c: In function 'main':
hiring.c:93:33: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   93 |   if (cnt_ < cnt || cnt_ == cnt && p_ * q > p * s * q_)
      |                     ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
hiring.c:80:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |  scanf("%d%lld", &n, &w);
      |  ^~~~~~~~~~~~~~~~~~~~~~~
hiring.c:82:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |   scanf("%d%d", &ss[i], &qq[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 28 / 28
• Subtask 3: 6 / 6
• Subtask 4: 6 / 6
• Subtask 5: 6 / 6
• Subtask 6: 6 / 6
• Subtask 7: 6 / 6
• Subtask 8: 6 / 6
• Subtask 9: 6 / 6