Submission #544615

# Submission time Handle Problem Language Result Execution time Memory
544615 2022-04-02T13:36:47 Z rainboy Demarcation (BOI14_demarcation) C
100 / 100
145 ms 8460 KB
/* upsolve after reading analysis */
#include <stdio.h>

#define N	100000
#define M	(N * 2)

unsigned int X = 12345;

int abs(int a) { return a > 0 ? a : -a; }

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

void flip(int *xx, int *yy, int n) {
	int i, j, tmp;

	for (i = 0, j = n - 1; i < j; i++, j--) {
		tmp = xx[i], xx[i] = xx[j], xx[j] = tmp;
		tmp = yy[i], yy[i] = yy[j], yy[j] = tmp;
	}
	for (i = 0; i < n; i++)
		xx[i] = -xx[i];
}

void rotate(int *xx, int *yy, int n) {
	int i, tmp;

	for (i = 0; i < n; i++)
		tmp = xx[i], xx[i] = -yy[i], yy[i] = tmp;
}

int check1(int *xx1, int *yy1, int *xx2, int *yy2, int n) {
	int i_, j_, i, j, x, y;

	i_ = -1;
	for (i = 0; i < n; i++)
		if (i_ == -1 || xx1[i_] > xx1[i] || xx1[i_] == xx1[i] && yy1[i_] > yy1[i])
			i_ = i;
	j_ = -1;
	for (j = 0; j < n; j++)
		if (j_ == -1 || xx2[j_] > xx2[j] || xx2[j_] == xx2[j] && yy2[j_] > yy2[j])
			j_ = j;
	x = xx1[i_] - xx2[j_], y = yy1[i_] - yy2[j_];
	for (i = 0; i < n; i++)
		if (xx1[(i + i_) % n] - xx2[(i + j_) % n] != x || yy1[(i + i_) % n] - yy2[(i + j_) % n] != y)
			return 0;
	return 1;
}

int check_(int *xx1, int *yy1, int *xx2, int *yy2, int n) {
	int a, b;

	for (a = 0; a < 2; a++) {
		for (b = 0; b < 4; b++) {
			if (check1(xx1, yy1, xx2, yy2, n))
				return 1;
			rotate(xx2, yy2, n);
		}
		flip(xx2, yy2, n);
	}
	return 0;
}

int xx[N], yy[N], n;

int check(int i_, int j_, int x) {
	static int xx1[N], yy1[N], xx2[N], yy2[N];
	int n1, n2, i;

	n1 = 0;
	i = (i_ + 1) % n;
	while (1) {
		if (i == (i_ + 1) % n) {
			if (xx[i] != x) {
				xx1[n1] = x, yy1[n1] = yy[i], n1++;
				xx1[n1] = xx[i], yy1[n1] = yy[i], n1++;
			}
		} else if (i == j_) {
			if (xx[i] != x) {
				xx1[n1] = xx[i], yy1[n1] = yy[i], n1++;
				xx1[n1] = x, yy1[n1] = yy[i], n1++;
			}
			break;
		} else
			xx1[n1] = xx[i], yy1[n1] = yy[i], n1++;
		i = (i + 1) % n;
	}
	n2 = 0;
	i = (j_ + 1) % n;
	while (1) {
		if (i == (j_ + 1) % n) {
			if (xx[i] != x) {
				xx2[n2] = x, yy2[n2] = yy[i], n2++;
				xx2[n2] = xx[i], yy2[n2] = yy[i], n2++;
			}
		} else if (i == i_) {
			if (xx[i] != x) {
				xx2[n2] = xx[i], yy2[n2] = yy[i], n2++;
				xx2[n2] = x, yy2[n2] = yy[i], n2++;
			}
			break;
		} else
			xx2[n2] = xx[i], yy2[n2] = yy[i], n2++;
		i = (i + 1) % n;
	}
	return n1 == n2 && check_(xx1, yy1, xx2, yy2, n1);
}

int xx_[M], kk1[M], kk2[M], tt[M], m;
int iq[1 + M], pq[M], cnt;

int lt(int i, int j) {
	return xx_[i] != xx_[j] ? xx_[i] < xx_[j] : tt[i] > tt[j];
}

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 x, int k1, int k2, int t) {
	int i = m++;

	xx_[i] = x, kk1[i] = k1, kk2[i] = k2, tt[i] = t;
	pq[i] = ++cnt, pq_up(i);
}

int pq_remove_first() {
	int i = iq[1], j = iq[cnt--];

	if (j != i)
		pq[j] = 1, pq_dn(j);
	pq[i] = 0;
	return i;
}

int zz[1 + N], ll[1 + N], rr[1 + N], kk[1 + N], _, u_, l_, r_;

int node(int k) {
	zz[_] = rand_();
	ll[_] = rr[_] = 0;
	kk[_] = k;
	return _++;
}

void split(int u, int k) {
	int c;

	if (u == 0) {
		u_ = l_ = r_ = 0;
		return;
	}
	c = yy[k] - yy[kk[u]];
	if (c < 0) {
		split(rr[u], k);
		rr[u] = l_, l_ = u;
	} else if (c > 0) {
		split(ll[u], k);
		ll[u] = r_, r_ = u;
	} else {
		u_ = u, l_ = ll[u], r_ = rr[u];
		ll[u] = rr[u] = 0;
	}
}

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;
	}
}

void tr_add(int k) {
	split(u_, k);
	u_ = merge(merge(l_, node(k)), r_);
}

void tr_remove(int k) {
	split(u_, k);
	u_ = merge(l_, r_);
}

int tr_lower(int k) {
	int u = u_, k_ = -1;

	while (u)
		if (yy[kk[u]] > yy[k])
			k_ = kk[u], u = rr[u];
		else
			u = ll[u];
	return k_;
}

int tr_higher(int k) {
	int u = u_, k_ = -1;

	while (u)
		if (yy[kk[u]] < yy[k])
			k_ = kk[u], u = ll[u];
		else
			u = rr[u];
	return k_;
}

long long pp[N * 2];

void add(int i, int j, int x_) {
	if (xx[i] < xx[(i + 1) % n] && xx[j] > xx[(j + 1) % n]) {
		long long p, x;
		int x1, x2, x3, x4;

		p = j < i - 1 ? pp[i - 1] - pp[j] : pp[i - 1 + n] - pp[j];
		x1 = xx[i], x2 = xx[(j + 1) % n];
		if ((x = pp[n - 1] / 2 - p + x1 + x2) % 2 == 0) {
			x /= 2;
			x3 = xx[(i + 1) % n], x4 = xx[j];
			if (x >= x_ && x <= x3 && x <= x4)
				pq_add(x, i, j, 0);
		}
		x_ = 0;
	}
}

int main() {
	int i, i_, j, r, tmp;

	scanf("%d", &n);
	i_ = -1;
	for (i = 0; i < n; i++) {
		scanf("%d%d", &xx[i], &yy[i]);
		if (i_ == -1 || xx[i_] > xx[i] || xx[i_] == xx[i] && yy[i_] > yy[i])
			i_ = i;
	}
	if (xx[(i_ + 1) % n] != xx[i_])
		for (i = 0, j = n - 1; i < j; i++, j--) {
			tmp = xx[i], xx[i] = xx[j], xx[j] = tmp;
			tmp = yy[i], yy[i] = yy[j], yy[j] = tmp;
		}
	for (i = 0; i < n * 2; i++)
		pp[i] = abs(xx[i % n] - xx[(i + 1) % n]) + abs(yy[i % n] - yy[(i + 1) % n]);
	for (i = 1; i < n * 2; i++)
		pp[i] += pp[i - 1];
	if (pp[n - 1] % 2 != 0) {
		printf("NO\n");
		return 0;
	}
	for (r = 0; r < 2; r++) {
		int i_, j_, x_;

		m = 0, cnt = 0;
		_ = 1, u_ = 0;
		for (i = 0; i < n; i++)
			if (xx[i] != xx[(i + 1) % n]) {
				int x1 = xx[i], x2 = xx[(i + 1) % n];

				if (x1 > x2)
					tmp = x1, x1 = x2, x2 = tmp;
				pq_add(x1, i, i, 1), pq_add(x2, i, i, -1);
			}
		i_ = -1, j_ = -1, x_ = -1;
		while (cnt) {
			int h = pq_remove_first(), l, r;

			if (tt[h] == 1) {
				i = kk1[h], l = tr_lower(i), r = tr_higher(i);
				tr_add(i);
				if (l != -1)
					add(l, i, xx_[h]);
				if (r != -1)
					add(i, r, xx_[h]);
			} else if (tt[h] == -1) {
				i = kk1[h], l = tr_lower(i), r = tr_higher(i);
				tr_remove(i);
				if (l != -1 && r != -1)
					add(l, r, xx_[h] + 1);
			} else
				if (tr_higher(kk1[h]) == kk2[h]) {
					i_ = kk1[h], j_ = kk2[h], x_ = xx_[h];
					break;
				}
		}
		if (i_ != -1 && j_ != -1 && check(i_, j_, x_)) {
			if (r == 0)
				printf("%d %d %d %d\n", x_, yy[i_], x_, yy[j_]);
			else
				printf("%d %d %d %d\n", yy[i_], -x_, yy[j_], -x_);
			return 0;
		}
		rotate(xx, yy, n);
	}
	printf("NO\n");
	return 0;
}

Compilation message

demarcation.c: In function 'check1':
demarcation.c:38:57: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   38 |   if (i_ == -1 || xx1[i_] > xx1[i] || xx1[i_] == xx1[i] && yy1[i_] > yy1[i])
      |                                       ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
demarcation.c:42:57: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   42 |   if (j_ == -1 || xx2[j_] > xx2[j] || xx2[j_] == xx2[j] && yy2[j_] > yy2[j])
      |                                       ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
demarcation.c: In function 'main':
demarcation.c:254:53: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  254 |   if (i_ == -1 || xx[i_] > xx[i] || xx[i_] == xx[i] && yy[i_] > yy[i])
      |                                     ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
demarcation.c:250:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  250 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
demarcation.c:253:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  253 |   scanf("%d%d", &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 4 ms 1076 KB Output is correct
2 Correct 0 ms 292 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 7 ms 980 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 0 ms 288 KB Output is correct
8 Correct 0 ms 340 KB Output is correct
9 Correct 38 ms 7648 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 292 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 0 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 ms 292 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 1 ms 340 KB Output is correct
21 Correct 0 ms 340 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 0 ms 292 KB Output is correct
24 Correct 0 ms 340 KB Output is correct
25 Correct 0 ms 340 KB Output is correct
26 Correct 0 ms 340 KB Output is correct
27 Correct 0 ms 340 KB Output is correct
28 Correct 0 ms 340 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 296 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 292 KB Output is correct
5 Correct 0 ms 296 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 1 ms 296 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 0 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 0 ms 340 KB Output is correct
15 Correct 0 ms 292 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 1 ms 340 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 0 ms 340 KB Output is correct
24 Correct 0 ms 340 KB Output is correct
25 Correct 0 ms 340 KB Output is correct
26 Correct 0 ms 340 KB Output is correct
27 Correct 1 ms 340 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 1 ms 288 KB Output is correct
31 Correct 0 ms 340 KB Output is correct
32 Correct 2 ms 468 KB Output is correct
33 Correct 2 ms 464 KB Output is correct
34 Correct 1 ms 428 KB Output is correct
35 Correct 1 ms 428 KB Output is correct
36 Correct 2 ms 468 KB Output is correct
37 Correct 2 ms 452 KB Output is correct
38 Correct 1 ms 468 KB Output is correct
39 Correct 1 ms 424 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 4 ms 1108 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 288 KB Output is correct
4 Correct 6 ms 1092 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 340 KB Output is correct
9 Correct 40 ms 7672 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 292 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 292 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 0 ms 340 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 0 ms 340 KB Output is correct
20 Correct 0 ms 340 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 1 ms 292 KB Output is correct
24 Correct 1 ms 292 KB Output is correct
25 Correct 1 ms 292 KB Output is correct
26 Correct 0 ms 292 KB Output is correct
27 Correct 1 ms 340 KB Output is correct
28 Correct 0 ms 340 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 0 ms 340 KB Output is correct
31 Correct 0 ms 292 KB Output is correct
32 Correct 1 ms 340 KB Output is correct
33 Correct 0 ms 340 KB Output is correct
34 Correct 0 ms 340 KB Output is correct
35 Correct 2 ms 468 KB Output is correct
36 Correct 2 ms 464 KB Output is correct
37 Correct 1 ms 468 KB Output is correct
38 Correct 1 ms 340 KB Output is correct
39 Correct 2 ms 468 KB Output is correct
40 Correct 1 ms 468 KB Output is correct
41 Correct 2 ms 468 KB Output is correct
42 Correct 1 ms 340 KB Output is correct
43 Correct 2 ms 468 KB Output is correct
44 Correct 43 ms 3228 KB Output is correct
45 Correct 57 ms 4152 KB Output is correct
46 Correct 26 ms 2672 KB Output is correct
47 Correct 16 ms 1624 KB Output is correct
48 Correct 17 ms 1908 KB Output is correct
49 Correct 89 ms 7256 KB Output is correct
50 Correct 41 ms 6256 KB Output is correct
51 Correct 58 ms 7896 KB Output is correct
52 Correct 145 ms 8460 KB Output is correct
53 Correct 120 ms 6812 KB Output is correct
54 Correct 105 ms 6824 KB Output is correct
55 Correct 50 ms 3112 KB Output is correct
56 Correct 47 ms 7416 KB Output is correct
57 Correct 127 ms 7720 KB Output is correct
58 Correct 103 ms 7116 KB Output is correct
59 Correct 98 ms 7988 KB Output is correct
60 Correct 35 ms 3404 KB Output is correct
61 Correct 8 ms 1492 KB Output is correct
62 Correct 13 ms 2220 KB Output is correct
63 Correct 21 ms 2884 KB Output is correct
64 Correct 18 ms 2972 KB Output is correct
65 Correct 39 ms 2764 KB Output is correct
66 Correct 37 ms 6532 KB Output is correct