Submission #731641

#	Time	Username	Problem	Language	Result	Execution time	Memory
731641		rainboy	Swimming competition (LMIO18_plaukimo_varzybos)	C11	100 / 100	453 ms	11980 KiB

plaukimo_varzybos

#include <stdio.h>

#define N	1000000
#define INF	0x3f3f3f3f

unsigned int X = 12345;

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

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

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

int solve(int *xx, int n, int a, int b, int d) {
	static char dp[N + 1];
	int i, i_, j;

	dp[0] = 1;
	for (i = 0, i_ = -1, j = 1; j <= n; j++) {
		if (j >= a && dp[j - a])
			i_ = j - a;
		while (i < n && (j - i > b || xx[j - 1] - xx[i] > d))
			i++;
		dp[j] = i_ >= i;
	}
	return dp[n];
}

int main() {
	static int xx[N];
	int n, a, b, i, lower, upper, d;

	scanf("%d%d%d", &n, &a, &b);
	for (i = 0; i < n; i++)
		scanf("%d", &xx[i]);
	sort(xx, 0, n);
	lower = -1, upper = INF;
	while (upper - lower > 1) {
		d = (lower + upper) / 2;
		if (solve(xx, n, a, b, d))
			upper = d;
		else
			lower = d;
	}
	printf("%d\n", upper);
	return 0;
}

Compilation message (stderr)

plaukimo_varzybos.c: In function 'main':
plaukimo_varzybos.c:50:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |  scanf("%d%d%d", &n, &a, &b);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~
plaukimo_varzybos.c:52:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |   scanf("%d", &xx[i]);
      |   ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 40 / 40