Submission #486465

# Submission time Handle Problem Language Result Execution time Memory
486465 2021-11-11T18:00:27 Z rainboy Relay (COI16_relay) C
57 / 100
2000 ms 6980 KB
#include <stdio.h>

#define N	100000
#define M	100000

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;
}

long long cross(int x0, int y0, int x1, int y1, int x2, int y2) {
	return cross2(x1 - x0, y1 - y0, x2 - x0, y2 - y0);
}

int xx[N + M], yy[N + M], xx_[N * 2], yy_[N * 2], idx[N * 2];

int compare(int x1, int y1, int x2, int y2) {
	int sgn1 = x1 < 0 || x1 == 0 && y1 < 0 ? -1 : 1;
	int sgn2 = x2 < 0 || x2 == 0 && y2 < 0 ? -1 : 1;
	long long c;

	if (sgn1 != sgn2)
		return sgn1 - sgn2;
	c = cross2(x1, y1, x2, y2);
	return c == 0 ? 0 : (c > 0 ? -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(xx_[ii[j]], yy_[ii[j]], xx_[i_], yy_[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 intersect(int l1, int r1, int l2, int r2) {
	int l1r1 = l1 <= r1, r1l2 = r1 < l2, l2r2 = l2 <= r2, r2l1 = r2 < l1;

	return !(l1r1 && r1l2 && l2r2 || r1l2 && l2r2 && r2l1 || l2r2 && r2l1 && l1r1 || r2l1 && l1r1 && r1l2);
}

int main() {
	static int ii[N * 2], dd[N * 2 + 1];
	int n, n_, m, i, j, p, q, k;

	scanf("%d", &n);
	for (i = 0; i < n; i++)
		scanf("%d%d", &xx[i], &yy[i]);
	scanf("%d", &m);
	for (j = 0; j < m; j++)
		scanf("%d%d", &xx[n + j], &yy[n + j]);
	for (i = 0; i < n; i++)
		for (j = 0; j < m; j++) {
			p = (j - 1 + m) % m, q = (j + 1) % m;
			if (cross(xx[i], yy[i], xx[n + p], yy[n + p], xx[n + j], yy[n + j]) >= 0
					&& cross(xx[i], yy[i], xx[n + q], yy[n + q], xx[n + j], yy[n + j]) > 0)
				xx_[i << 1 | 0] = xx[i] - xx[n + j], yy_[i << 1 | 0] = yy[i] - yy[n + j];
			if (cross(xx[i], yy[i], xx[n + q], yy[n + q], xx[n + j], yy[n + j]) <= 0
					&& cross(xx[i], yy[i], xx[n + p], yy[n + p], xx[n + j], yy[n + j]) < 0)
				xx_[i << 1 | 1] = xx[n + j] - xx[i], yy_[i << 1 | 1] = yy[n + j] - yy[i];
		}
	for (i = 0; i < n * 2; i++)
		ii[i] = i;
	sort(ii, 0, n * 2);
	for (i = 0, n_ = 0; i < n * 2; i++)
		idx[ii[i]] = i + 1 == n * 2 || compare(xx_[ii[i + 1]], yy_[ii[i + 1]], xx_[ii[i]], yy_[ii[i]]) != 0 ? n_++ : n_;
	for (i = 1; i < n; i++) {
		int l = idx[i << 1 | 0], r = idx[i << 1 | 1];

		if (intersect(idx[0 << 1 | 0], idx[0 << 1 | 1], l, r)) {
			if (l < r)
				dd[l]++, dd[r + 1]--;
			else
				dd[l]++, dd[n_]--, dd[0]++, dd[r + 1]--;
		}
	}
	for (i = 1; i < n_; i++)
		dd[i] += dd[i - 1];
	for (i = 0; i < n_; i++)
		if (dd[i] > 0)
			dd[i] = 1;
	for (i = 1; i < n_; i++)
		dd[i] += dd[i - 1];
	k = 0;
	for (i = 1; i < n; i++) {
		int l = idx[i << 1 | 0], r = idx[i << 1 | 1];

		if ((l < r ? dd[r] - (l == 0 ? 0 : dd[l - 1]) : dd[n_ - 1] - dd[l - 1] + dd[r]) > 0)
			k++;
	}
	printf("%d\n", k);
	return 0;
}

Compilation message

relay.c: In function 'compare':
relay.c:23:31: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   23 |  int sgn1 = x1 < 0 || x1 == 0 && y1 < 0 ? -1 : 1;
      |                       ~~~~~~~~^~~~~~~~~
relay.c:24:31: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   24 |  int sgn2 = x2 < 0 || x2 == 0 && y2 < 0 ? -1 : 1;
      |                       ~~~~~~~~^~~~~~~~~
relay.c: In function 'intersect':
relay.c:58:24: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   58 |  return !(l1r1 && r1l2 && l2r2 || r1l2 && l2r2 && r2l1 || l2r2 && r2l1 && l1r1 || r2l1 && l1r1 && r1l2);
      |           ~~~~~~~~~~~~~^~~~~~~
relay.c:58:72: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   58 |  return !(l1r1 && r1l2 && l2r2 || r1l2 && l2r2 && r2l1 || l2r2 && r2l1 && l1r1 || r2l1 && l1r1 && r1l2);
      |                                                           ~~~~~~~~~~~~~^~~~~~~
relay.c:58:96: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   58 |  return !(l1r1 && r1l2 && l2r2 || r1l2 && l2r2 && r2l1 || l2r2 && r2l1 && l1r1 || r2l1 && l1r1 && r1l2);
      |                                                                                   ~~~~~~~~~~~~~^~~~~~~
relay.c: In function 'main':
relay.c:65:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
relay.c:67:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |   scanf("%d%d", &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
relay.c:68:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |  scanf("%d", &m);
      |  ^~~~~~~~~~~~~~~
relay.c:70:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |   scanf("%d%d", &xx[n + j], &yy[n + j]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 91 ms 356 KB Output is correct
12 Correct 90 ms 580 KB Output is correct
13 Correct 48 ms 452 KB Output is correct
14 Correct 52 ms 428 KB Output is correct
15 Correct 43 ms 452 KB Output is correct
16 Correct 44 ms 432 KB Output is correct
17 Correct 46 ms 444 KB Output is correct
18 Correct 51 ms 432 KB Output is correct
19 Correct 50 ms 564 KB Output is correct
20 Correct 48 ms 432 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 327 ms 4952 KB Output is correct
12 Correct 342 ms 6860 KB Output is correct
13 Correct 199 ms 6852 KB Output is correct
14 Correct 194 ms 6936 KB Output is correct
15 Correct 218 ms 6932 KB Output is correct
16 Correct 222 ms 6980 KB Output is correct
17 Correct 209 ms 6856 KB Output is correct
18 Correct 226 ms 6940 KB Output is correct
19 Correct 216 ms 6852 KB Output is correct
20 Correct 209 ms 6888 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 91 ms 356 KB Output is correct
12 Correct 90 ms 580 KB Output is correct
13 Correct 48 ms 452 KB Output is correct
14 Correct 52 ms 428 KB Output is correct
15 Correct 43 ms 452 KB Output is correct
16 Correct 44 ms 432 KB Output is correct
17 Correct 46 ms 444 KB Output is correct
18 Correct 51 ms 432 KB Output is correct
19 Correct 50 ms 564 KB Output is correct
20 Correct 48 ms 432 KB Output is correct
21 Correct 327 ms 4952 KB Output is correct
22 Correct 342 ms 6860 KB Output is correct
23 Correct 199 ms 6852 KB Output is correct
24 Correct 194 ms 6936 KB Output is correct
25 Correct 218 ms 6932 KB Output is correct
26 Correct 222 ms 6980 KB Output is correct
27 Correct 209 ms 6856 KB Output is correct
28 Correct 226 ms 6940 KB Output is correct
29 Correct 216 ms 6852 KB Output is correct
30 Correct 209 ms 6888 KB Output is correct
31 Execution timed out 2080 ms 5776 KB Time limit exceeded
32 Halted 0 ms 0 KB -