Submission #945363

#	Time	Username	Problem	Language	Result	Execution time	Memory
945363		rainboy	Taxis (POI13_tak)	C11	100 / 100	119 ms	4228 KiB

tak

#include <stdio.h>

#define N	500000
#define INF	0x3f3f3f3f

unsigned int X = 12345;

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

void sort(long long *dd, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r;
		long long d = dd[l + rand_() % (r - l)], tmp;

		while (j < k)
			if (dd[j] == d)
				j++;
			else if (dd[j] < d) {
				tmp = dd[i], dd[i] = dd[j], dd[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = dd[j], dd[j] = dd[k], dd[k] = tmp;
			}
		sort(dd, l, i);
		l = k;
	}
}

int main() {
	static long long dd[N];
	int n, i;
	long long m, l, l_, x;

	scanf("%lld%lld%d", &m, &l, &n);
	for (i = 0; i < n; i++)
		scanf("%lld", &dd[i]);
	sort(dd, 0, n);
	x = 0;
	for (i = n - 1; i >= 0 && x < l; i--) {
		if (l - x > dd[i]) {
			printf("0\n");
			return 0;
		}
		x += dd[i] - (l - x);
	}
	if (x < l) {
		printf("0\n");
		return 0;
	}
	if (x >= m) {
		printf("%d\n", n - 1 - i);
		return 0;
	}
	if (i >= 0 && dd[i] >= m - l) {
		printf("%d\n", n - i);
		return 0;
	}
	i = 0;
	while (i < n && dd[i] < m - l)
		i++;
	if (i == n) {
		printf("0\n");
		return 0;
	}
	l_ = l - (dd[i] - (m - l)) / 2;
	n--;
	while (i < n)
		dd[i] = dd[i + 1], i++;
	x = 0;
	for (i = n - 1; i >= 0 && x < l_; i--) {
		if (l - x > dd[i]) {
			printf("0\n");
			return 0;
		}
		x += dd[i] - (l - x);
	}
	printf("%d\n", x < l_ ? 0 : n - i);
	return 0;
}

Compilation message (stderr)

tak.c: In function 'main':
tak.c:37:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |  scanf("%lld%lld%d", &m, &l, &n);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tak.c:39:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |   scanf("%lld", &dd[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10