Submission #944563

#	Time	Username	Problem	Language	Result	Execution time	Memory
944563		rainboy	전봇대 (KOI13_pole)	C11	100 / 100	12 ms	2476 KiB

pole

#include <stdio.h>

#define N	100000

long long abs_(long long a) { return a > 0 ? a : -a; }
long long min(long long a, long long b) { return a < b ? a : b; }

unsigned int X = 12345;

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

int tt[N];

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)
			if (tt[ii[j]] == tt[i_])
				j++;
			else if (tt[ii[j]] < tt[i_]) {
				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 main() {
	static int xx[N], ii[N];
	int n, i, t;
	long long a, ans1, ans2;

	scanf("%d", &n);
	if (n == 1) {
		printf("0\n");
		return 0;
	}
	for (i = 0; i < n; i++)
		scanf("%d", &xx[i]);
	for (i = 1; i < n; i++)
		xx[i] -= xx[0];
	for (i = 1; i < n; i++)
		tt[i] = xx[i] / i;
	for (i = 1; i < n; i++)
		ii[i] = i;
	sort(ii, 1, n);
	a = (long long) n * (n - 1) / 2, t = 0;
	for (i = 1; i < n; i++)
		if ((a -= ii[i] * 2) <= 0) {
			t = tt[ii[i]];
			break;
		}
	ans1 = 0;
	for (i = 1; i < n; i++)
		ans1 += abs_(xx[i] - (long long) t * i);
	ans2 = 0;
	for (i = 1; i < n; i++)
		ans2 += abs_(xx[i] - (long long) (t + 1) * i);
	printf("%lld\n", min(ans1, ans2));
	return 0;
}

Compilation message (stderr)

pole.c: In function 'main':
pole.c:40:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
pole.c:46:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |   scanf("%d", &xx[i]);
      |   ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 21 / 21
• Subtask 3: 31 / 31
• Subtask 4: 37 / 37