제출 #381226

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
381226		rainboy	원 고르기 (APIO18_circle_selection)	C11	12 / 100	1069 ms	16492 KiB

circle_selection

#include <stdio.h>

#define N	300000

unsigned int X = 12345;

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

int xx[N], yy[N], rr_[N], yy_[N * 2];

int intersect(int i, int j) {
	long long x = xx[i] - xx[j], y = yy[i] - yy[j], r = rr_[i] + rr_[j];

	return x * x + y * y <= r * r;
}

int compare_r(int i, int j) {
	return rr_[i] != rr_[j] ? rr_[j] - rr_[i] : i - j;
}

int compare_y(int i, int j) {
	return yy_[i] == yy_[j] ? (i & 1) - (j & 1) : (yy_[i] < yy_[j] ? -1 : 1);
}

int (*compare)(int, int);

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 zz[1 + N], ll[1 + N], rr[1 + N], ii_[1 + N], u_, l_, r_;

int node(int i) {
	static int _ = 1;

	zz[_] = rand_();
	ii_[_] = i;
	return _++;
}

void split(int u, int i) {
	if (u == 0) {
		u_ = l_ = r_ = 0;
		return;
	}
	if (xx[ii_[u]] < xx[i]) {
		split(rr[u], i);
		rr[u] = l_, l_ = u;
	} else {
		split(ll[u], i);
		ll[u] = r_, r_ = u;
	}
}

int merge(int u, int v) {
	if (u == 0)
		return v;
	if (v == 0)
		return u;
	if (zz[u] < zz[v]) {
		rr[u] = merge(rr[u], v);
		return u;
	} else {
		ll[v] = merge(u, ll[v]);
		return v;
	}
}

int first(int u) {
	return ll[u] == 0 ? u : first(ll[u]);
}

int last(int u) {
	return rr[u] == 0 ? u : last(rr[u]);
}

int remove_first(int u) {
	if (ll[u] == 0)
		return rr[u];
	ll[u] = remove_first(ll[u]);
	return u;
}

int remove_last(int u) {
	if (rr[u] == 0)
		return ll[u];
	rr[u] = remove_last(rr[u]);
	return u;
}

int main() {
	static int ii[N * 2], pp[N];
	static char used[N];
	int n, h, i, segs;

	scanf("%d", &n);
	segs = 1;
	for (i = 0; i < n; i++) {
		scanf("%d%d%d", &xx[i], &yy[i], &rr_[i]);
		if (yy[i] != 0)
			segs = 0;
	}
	if (/*n <= 5000*/0) {
		while (1) {
			int i_;

			i_ = -1;
			for (i = 0; i < n; i++)
				if (!used[i] && (i_ == -1 || rr_[i_] < rr_[i]))
					i_ = i;
			if (i_ == -1)
				break;
			for (i = 0; i < n; i++)
				if (!used[i] && intersect(i_, i))
					used[i] = 1, pp[i] = i_;
		}
	} else if (segs) {
		for (i = 0; i < n; i++)
			ii[i] = i;
		compare = compare_r, sort(ii, 0, n);
		for (h = 0; h < n; h++) {
			int i = ii[h], p, q;

			split(u_, i);
			p = l_ ? ii_[last(l_)] : -1, q = r_ ? ii_[first(r_)] : -1;
			if (p != -1 && xx[p] + rr_[p] < xx[i] - rr_[i])
				p = -1;
			if (q != -1 && xx[q] - rr_[q] > xx[i] + rr_[i])
				q = -1;
			if (p == -1 && q == -1)
				pp[i] = i, u_ = node(i);
			else
				pp[i] = q == -1 || p != -1 && (rr_[p] > rr_[q] || rr_[p] == rr_[q] && p < q) ? p : q;
			u_ = merge(merge(l_, u_), r_);
		}
	} else {
		for (i = 0; i < n; i++)
			yy_[i << 1 | 0] = yy[i] - rr_[i], yy_[i << 1 | 1] = yy[i] + rr_[i];
		for (i = 0; i < n * 2; i++)
			ii[i] = i;
		compare = compare_y, sort(ii, 0, n * 2);
		for (i = 0; i < n; i++)
			pp[i] = i;
		for (h = 0; h < n * 2; h++) {
			int i_ = ii[h], p, q;

			i = i_ >> 1;
			if ((i_ & 1) == 0) {
				split(u_, i);
				p = l_ ? ii_[last(l_)] : -1, q = r_ ? ii_[first(r_)] : -1;
				if (p != -1 && intersect(p, i))
					l_ = remove_last(l_), pp[i] = pp[p] = p == -1 || i != -1 && (rr_[i] > rr_[p] || rr_[i] == rr_[p] && i < p) ? i : p;
				else if (q != -1 && intersect(q, i))
					r_ = remove_first(r_), pp[i] = pp[q] = q == -1 || i != -1 && (rr_[i] > rr_[q] || rr_[i] == rr_[q] && i < q) ? i : q;
				else
					u_ = node(i);
				u_ = merge(merge(l_, u_), r_);
			} else {
				split(u_, i);
				p = l_ ? ii_[last(l_)] : -1, q = r_ ? ii_[first(r_)] : -1;
				if (p != -1 && q != -1 && intersect(p, q))
					l_ = remove_last(l_), r_ = remove_first(r_), pp[p] = pp[q] = q == -1 || p != -1 && (rr_[p] > rr_[q] || rr_[p] == rr_[q] && p < q) ? p : q;
				u_ = merge(l_, r_);
			}
		}
	}
	for (i = 0; i < n; i++)
		printf("%d ", pp[i] + 1);
	printf("\n");
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

circle_selection.c: In function 'main':
circle_selection.c:153:72: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  153 |     pp[i] = q == -1 || p != -1 && (rr_[p] > rr_[q] || rr_[p] == rr_[q] && p < q) ? p : q;
      |                                                       ~~~~~~~~~~~~~~~~~^~~~~~~~
circle_selection.c:153:32: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  153 |     pp[i] = q == -1 || p != -1 && (rr_[p] > rr_[q] || rr_[p] == rr_[q] && p < q) ? p : q;
      |                        ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
circle_selection.c:172:103: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  172 |      l_ = remove_last(l_), pp[i] = pp[p] = p == -1 || i != -1 && (rr_[i] > rr_[p] || rr_[i] == rr_[p] && i < p) ? i : p;
      |                                                                                      ~~~~~~~~~~~~~~~~~^~~~~~~~
circle_selection.c:172:63: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  172 |      l_ = remove_last(l_), pp[i] = pp[p] = p == -1 || i != -1 && (rr_[i] > rr_[p] || rr_[i] == rr_[p] && i < p) ? i : p;
      |                                                       ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
circle_selection.c:174:104: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  174 |      r_ = remove_first(r_), pp[i] = pp[q] = q == -1 || i != -1 && (rr_[i] > rr_[q] || rr_[i] == rr_[q] && i < q) ? i : q;
      |                                                                                       ~~~~~~~~~~~~~~~~~^~~~~~~~
circle_selection.c:174:64: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  174 |      r_ = remove_first(r_), pp[i] = pp[q] = q == -1 || i != -1 && (rr_[i] > rr_[q] || rr_[i] == rr_[q] && i < q) ? i : q;
      |                                                        ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
circle_selection.c:182:126: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  182 |      l_ = remove_last(l_), r_ = remove_first(r_), pp[p] = pp[q] = q == -1 || p != -1 && (rr_[p] > rr_[q] || rr_[p] == rr_[q] && p < q) ? p : q;
      |                                                                                                             ~~~~~~~~~~~~~~~~~^~~~~~~~
circle_selection.c:182:86: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  182 |      l_ = remove_last(l_), r_ = remove_first(r_), pp[p] = pp[q] = q == -1 || p != -1 && (rr_[p] > rr_[q] || rr_[p] == rr_[q] && p < q) ? p : q;
      |                                                                              ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
circle_selection.c:116:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  116 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
circle_selection.c:119:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  119 |   scanf("%d%d%d", &xx[i], &yy[i], &rr_[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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