oj.uz

답안 #545881

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
545881 2022-04-05T15:51:10 Z rainboy Printed Circuit Board (CEOI12_circuit) C
85 / 100
 100 ms 6096 KB 
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <stdio.h>
#include <string.h>
 
#define N	200000
 
unsigned int X = 12345;
 
int rand_() {
	return (X *= 3) >> 1;
}
 
long long cross2(int x1, int y1, int x2, int y2) {
	return (long long) x1 * y2 - (long long) x2 * y1;
}
 
int xx[N], yy[N], ii[N * 2];
 
long long cross(int i, int j, int k) {
	return cross2(xx[j] - xx[i], yy[j] - yy[i], xx[k] - xx[i], yy[k] - yy[i]);
}
 
int cmp(int h1, int h2) {
	long long c = cross2(xx[ii[h1]], yy[ii[h1]], xx[ii[h2]], yy[ii[h2]]);
 
	return c ? (c < 0 ? -1 : 1) : (h1 & 1) - (h2 & 1);
}
 
void sort(int *hh, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r, h_ = hh[l + rand_() % (r - l)], tmp;
 
		while (j < k) {
			int c = cmp(hh[j], h_);
 
			if (c == 0)
				j++;
			else if (c < 0) {
				tmp = hh[i], hh[i] = hh[j], hh[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = hh[j], hh[j] = hh[k], hh[k] = tmp;
			}
		}
		sort(hh, l, i);
		l = k;
	}
}
 
int iq[1 + N], pq[N], cnt, x_, y_;
 
int lt(int i, int j) {
	int i0 = ii[i << 1 | 0], i1 = ii[i << 1 | 1], j0 = ii[j << 1 | 0], j1 = ii[j << 1 | 1];
 
	return cross(i0, i1, j0) >= 0 && cross(i0, i1, j1) >= 0 || cross(j0, j1, i0) <= 0 && cross(j0, j1, i1) <= 0;
}
 
int p2(int p) {
	return (p *= 2) > cnt ? 0 : (p < cnt && lt(iq[p + 1], iq[p]) ? p + 1 : p);
}
 
void pq_up(int i) {
	int p, q, j;
 
	for (p = pq[i]; (q = p / 2) && lt(i, j = iq[q]); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}
 
void pq_dn(int i) {
	int p, q, j;
 
	for (p = pq[i]; (q = p2(p)) && lt(j = iq[q], i); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}
 
void pq_add(int i) {
	pq[i] = ++cnt, pq_up(i);
}
 
void pq_remove(int i) {
	if (pq[i]) {
		int j = iq[cnt--];
 
		if (j != i)
			pq[j] = pq[i], pq_up(j), pq_dn(j);
		pq[i] = 0;
	}
}
 
int main() {
	static int hh[N * 2];
	static char visible[N];
	int n, n_, g, h, h_, i;
 
	scanf("%d", &n);
	for (i = 0; i < n; i++)
		scanf("%d%d", &xx[i], &yy[i]);
	n_ = 0;
	for (i = 0; i < n; i++) {
		long long c = cross2(xx[i], yy[i], xx[(i + 1) % n], yy[(i + 1) % n]);
 
		if (c < 0) {
			ii[i << 1 | 0] = i, ii[i << 1 | 1] = (i + 1) % n;
			hh[n_++] = i << 1 | 0, hh[n_++] = i << 1 | 1;
		} else if (c > 0) {
			ii[i << 1 | 0] = (i + 1) % n, ii[i << 1 | 1] = i;
			hh[n_++] = i << 1 | 0, hh[n_++] = i << 1 | 1;
		}
	}
	sort(hh, 0, n_);
	memset(visible, 1, n * sizeof *visible);
	for (h = 0; h < n_; h++) {
		h_ = hh[h];
		x_ = xx[ii[h_]], y_ = yy[ii[h_]];
		if ((h_ & 1) == 0)
			pq_add(h_ >> 1);
		else
			pq_remove(h_ >> 1);
		if (cnt) {
			i = iq[1];
			if (cross(ii[i << 1 | 0], ii[i << 1 | 1], ii[h_]) > 0)
				visible[ii[h_]] = 0;
		}
	}
	for (h = 0; h < n_; h = h_) {
		int h1, i_;
 
		h1 = hh[h], h_ = h, i_ = -1;
		while (h_ < n_ && cross2(xx[ii[h1]], yy[ii[h1]], xx[ii[hh[h_]]], yy[ii[hh[h_]]]) == 0) {
			i = ii[hh[h_++]];
			if (i_ == -1 || xx[i_] > xx[i])
				i_ = i;
		}
		for (g = h; g < h_; g++) {
			i = ii[hh[g]];
			if (i != i_)
				visible[i] = 0;
		}
	}
	cnt = 0;
	for (i = 0; i < n; i++)
		if (visible[i])
			cnt++;
	printf("%d\n", cnt);
	for (i = 0; i < n; i++)
		if (visible[i])
			printf("%d ", i + 1);
	printf("\n");
	return 0;
}

Compilation message

circuit.c:2: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    2 | #pragma GCC optimization ("O3")
      | 
circuit.c:3: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    3 | #pragma GCC optimization ("unroll-loops")
      | 
circuit.c: In function 'lt':
circuit.c:58:32: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   58 |  return cross(i0, i1, j0) >= 0 && cross(i0, i1, j1) >= 0 || cross(j0, j1, i0) <= 0 && cross(j0, j1, i1) <= 0;
      |         ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
circuit.c: In function 'main':
circuit.c:100:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
circuit.c:102:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |   scanf("%d%d", &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
85.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 2 ms 340 KB Output is correct
4 Correct 2 ms 340 KB Output is correct
5 Correct 7 ms 556 KB Output is correct
6 Correct 6 ms 596 KB Output is correct
7 Correct 14 ms 852 KB Output is correct
8 Correct 5 ms 468 KB Output is correct
9 Correct 7 ms 596 KB Output is correct
10 Correct 7 ms 596 KB Output is correct
11 Correct 7 ms 596 KB Output is correct
12 Correct 11 ms 852 KB Output is correct
13 Correct 21 ms 1076 KB Output is correct
14 Correct 20 ms 1444 KB Output is correct
15 Correct 27 ms 1612 KB Output is correct
16 Correct 55 ms 3028 KB Output is correct
17 Correct 74 ms 3116 KB Output is correct
18 Execution timed out 109 ms 5868 KB Time limit exceeded
19 Execution timed out 111 ms 5924 KB Time limit exceeded
20 Execution timed out 164 ms 6096 KB Time limit exceeded