Submission #485920

#	Time	Username	Problem	Language	Result	Execution time	Memory
485920		rainboy	ČVENK (COI15_cvenk)	C11	100 / 100	431 ms	1476 KiB

cvenk

#include <stdio.h>
#include <time.h>

#define N	100000
#define L	29
#define INF	0x3f3f3f3f3f3f3f3fLL

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

unsigned int X = 12345;

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

void lca(int x1, int y1, int x2, int y2, int *x, int *y, int l) {
	if (l == 0)
		*x = 0, *y = 0;
	else {
		int n = 1 << l - 1;

		if (x1 >= n && y1 < n && x2 >= n && y2 < n)
			lca(x1 - n, y1, x2 - n, y2, x, y, l - 1), *x += n;
		else if (x1 < n && y1 >= n && x2 < n && y2 >= n)
			lca(x1, y1 - n, x2, y2 - n, x, y, l - 1), *y += n;
		else {
			if (x1 >= n && y1 < n)
				x1 = n - 1, y1 = 0;
			else if (x1 < n && y1 >= n)
				x1 = 0, y1 = n - 1;
			if (x2 >= n && y2 < n)
				x2 = n - 1, y2 = 0;
			else if (x2 < n && y2 >= n)
				x2 = 0, y2 = n - 1;
			lca(x1, y1, x2, y2, x, y, l - 1);
		}
	}
}

long long dist(int x1, int y1, int x2, int y2) {
	int x, y;

	lca(x1, y1, x2, y2, &x, &y, L);
	return (long long) (x1 + y1) + (x2 + y2) - (long long) (x + y) * 2;
}

int xx[N], yy[N];

int compare(int i, int j) {
	int x, y, x_, y_;

	if (xx[i] == xx[j] && yy[i] == yy[j])
		return 0;
	lca(xx[i], yy[i], xx[j], yy[j], &x, &y, L);
	if (xx[i] == x && yy[i] == y)
		return -1;
	if (xx[j] == x && yy[j] == y)
		return 1;
	lca(xx[i], yy[i], x + 1, y, &x_, &y_, L);
	return x_ == x + 1 ? -1 : 1;
}

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 main() {
	static int ii[N];
	int n, i;
	long long ans;

	scanf("%d", &n);
	for (i = 0; i < n; i++) {
		scanf("%d%d", &xx[i], &yy[i]);
		ii[i] = i;
	}
	sort(ii, 0, n);
	ans = 0;
	for (i = 0; i < n; i++) {
		int u = ii[i], v = ii[(i + n / 2) % n];

		ans += dist(xx[u], yy[u], xx[v], yy[v]);
	}
	ans /= 2;
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

cvenk.c: In function 'lca':
cvenk.c:20:18: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   20 |   int n = 1 << l - 1;
      |                ~~^~~
cvenk.c: In function 'main':
cvenk.c:90:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
cvenk.c:92:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |   scanf("%d%d", &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 21 / 21
• Subtask 3: 22 / 22
• Subtask 4: 40 / 40