oj.uz

Submission #486523

# Submission time Handle Problem Language Result Execution time Memory
486523 2021-11-11T21:56:51 Z rainboy Relay (COI16_relay) C
100 / 100
 137 ms 9540 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;
}

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

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 compare1(int i, int j) {
	return xx[i] != xx[j] ? xx[i] - xx[j] : yy[i] - yy[j];
}

int compare2(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 = compare2(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 l, r;

void find_tangents(int o, int *p, int *q) {
	int lower, upper;

	if (compare1(o, n + l) < 0) {
		lower = -1, upper = (r - l + m) % m;
		while (upper - lower > 1) {
			int i = (lower + upper) / 2;

			if (cross(o, n + (l + i) % m, n + (l + i + 1) % m) >= 0)
				lower = i;
			else
				upper = i;
		}
		*p = (l + upper) % m;
		lower = -1, upper = (l - r + m) % m;
		while (upper - lower > 1) {
			int i = (lower + upper) / 2;

			if (cross(o, n + (l - i + m) % m, n + (l - (i + 1) + m) % m) <= 0)
				lower = i;
			else
				upper = i;
		}
		*q = (l - upper + m) % m;
	} else if (compare1(o, n + r) > 0) {
		lower = -1, upper = (l - r + m) % m;
		while (upper - lower > 1) {
			int i = (lower + upper) / 2;

			if (cross(o, n + (r + i) % m, n + (r + i + 1) % m) >= 0)
				lower = i;
			else
				upper = i;
		}
		*p = (r + upper) % m;
		lower = -1, upper = (r - l + m) % m;
		while (upper - lower > 1) {
			int i = (lower + upper) / 2;

			if (cross(o, n + (r - i + m) % m, n + (r - (i + 1) + m) % m) <= 0)
				lower = i;
			else
				upper = i;
		}
		*q = (r - upper + m) % m;
	} else if (cross(o, n + l, n + r) > 0) {
		lower = -1, upper = (r - l + m) % m;
		while (upper - lower > 1) {
			int i = (lower + upper) / 2;

			if (compare1(o, n + (r - i + m) % m) < 0 && cross(o, n + (r - i + m) % m, n + (r - (i + 1) + m) % m) > 0)
				lower = i;
			else
				upper = i;
		}
		*p = (r - upper + m) % m;
		lower = -1, upper = (r - l + m) % m;
		while (upper - lower > 1) {
			int i = (lower + upper) / 2;

			if (compare1(o, n + (l + i) % m) > 0 && cross(o, n + (l + i) % m, n + (l + i + 1) % m) < 0)
				lower = i;
			else
				upper = i;
		}
		*q = (l + upper) % m;
	} else {
		lower = -1, upper = (l - r + m) % m;
		while (upper - lower > 1) {
			int i = (lower + upper) / 2;

			if (compare1(o, n + (l - i + m) % m) > 0 && cross(o, n + (l - i + m) % m, n + (l - (i + 1) + m) % m) > 0)
				lower = i;
			else
				upper = i;
		}
		*p = (l - upper + m) % m;
		lower = -1, upper = (l - r + m) % m;
		while (upper - lower > 1) {
			int i = (lower + upper) / 2;

			if (compare1(o, n + (r + i) % m) < 0 && cross(o, n + (r + i) % m, n + (r + i + 1) % m) < 0)
				lower = i;
			else
				upper = i;
		}
		*q = (r + upper) % m;
	}
}

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

	scanf("%d", &n);
	for (i = 0; i < n; i++)
		scanf("%d%d", &xx[i], &yy[i]);
	scanf("%d", &m);
	l = -1, r = -1;
	for (j = m - 1; j >= 0; j--) {
		scanf("%d%d", &xx[n + j], &yy[n + j]);
		if (l == -1 || compare1(n + l, n + j) > 0)
			l = j;
		if (r == -1 || compare1(n + r, n + j) < 0)
			r = j;
	}
	for (i = 0; i < n; i++) {
		int p, q;

		find_tangents(i, &p, &q);
		xx_[i << 1 | 0] = xx[i] - xx[n + p], yy_[i << 1 | 0] = yy[i] - yy[n + p];
		xx_[i << 1 | 1] = xx[n + q] - xx[i], yy_[i << 1 | 1] = yy[n + q] - 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 || compare2(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 'compare2':
relay.c:27:31: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   27 |  int sgn1 = x1 < 0 || x1 == 0 && y1 < 0 ? -1 : 1;
      |                       ~~~~~~~~^~~~~~~~~
relay.c:28:31: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   28 |  int sgn2 = x2 < 0 || x2 == 0 && y2 < 0 ? -1 : 1;
      |                       ~~~~~~~~^~~~~~~~~
relay.c: In function 'intersect':
relay.c:62:24: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   62 |  return !(l1r1 && r1l2 && l2r2 || r1l2 && l2r2 && r2l1 || l2r2 && r2l1 && l1r1 || r2l1 && l1r1 && r1l2);
      |           ~~~~~~~~~~~~~^~~~~~~
relay.c:62:72: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   62 |  return !(l1r1 && r1l2 && l2r2 || r1l2 && l2r2 && r2l1 || l2r2 && r2l1 && l1r1 || r2l1 && l1r1 && r1l2);
      |                                                           ~~~~~~~~~~~~~^~~~~~~
relay.c:62:96: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   62 |  return !(l1r1 && r1l2 && l2r2 || r1l2 && l2r2 && r2l1 || l2r2 && r2l1 && l1r1 || r2l1 && l1r1 && r1l2);
      |                                                                                   ~~~~~~~~~~~~~^~~~~~~
relay.c: In function 'main':
relay.c:161:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  161 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
relay.c:163:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  163 |   scanf("%d%d", &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
relay.c:164:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  164 |  scanf("%d", &m);
      |  ^~~~~~~~~~~~~~~
relay.c:167:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  167 |   scanf("%d%d", &xx[n + j], &yy[n + j]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 0 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct

Subtask #2
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 0 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 3 ms 588 KB Output is correct
12 Correct 3 ms 528 KB Output is correct
13 Correct 3 ms 460 KB Output is correct
14 Correct 3 ms 460 KB Output is correct
15 Correct 3 ms 460 KB Output is correct
16 Correct 4 ms 460 KB Output is correct
17 Correct 4 ms 460 KB Output is correct
18 Correct 4 ms 460 KB Output is correct
19 Correct 4 ms 460 KB Output is correct
20 Correct 3 ms 460 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 0 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 77 ms 6824 KB Output is correct
12 Correct 75 ms 6852 KB Output is correct
13 Correct 70 ms 6876 KB Output is correct
14 Correct 72 ms 6884 KB Output is correct
15 Correct 111 ms 6864 KB Output is correct
16 Correct 95 ms 6864 KB Output is correct
17 Correct 94 ms 6924 KB Output is correct
18 Correct 95 ms 6908 KB Output is correct
19 Correct 99 ms 6860 KB Output is correct
20 Correct 94 ms 6852 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 0 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 3 ms 588 KB Output is correct
12 Correct 3 ms 528 KB Output is correct
13 Correct 3 ms 460 KB Output is correct
14 Correct 3 ms 460 KB Output is correct
15 Correct 3 ms 460 KB Output is correct
16 Correct 4 ms 460 KB Output is correct
17 Correct 4 ms 460 KB Output is correct
18 Correct 4 ms 460 KB Output is correct
19 Correct 4 ms 460 KB Output is correct
20 Correct 3 ms 460 KB Output is correct
21 Correct 77 ms 6824 KB Output is correct
22 Correct 75 ms 6852 KB Output is correct
23 Correct 70 ms 6876 KB Output is correct
24 Correct 72 ms 6884 KB Output is correct
25 Correct 111 ms 6864 KB Output is correct
26 Correct 95 ms 6864 KB Output is correct
27 Correct 94 ms 6924 KB Output is correct
28 Correct 95 ms 6908 KB Output is correct
29 Correct 99 ms 6860 KB Output is correct
30 Correct 94 ms 6852 KB Output is correct
31 Correct 137 ms 8088 KB Output is correct
32 Correct 122 ms 9540 KB Output is correct
33 Correct 104 ms 8272 KB Output is correct
34 Correct 107 ms 8308 KB Output is correct
35 Correct 130 ms 8260 KB Output is correct
36 Correct 128 ms 8244 KB Output is correct
37 Correct 128 ms 8236 KB Output is correct
38 Correct 137 ms 8260 KB Output is correct
39 Correct 120 ms 7876 KB Output is correct
40 Correct 120 ms 7856 KB Output is correct