oj.uz

Submission #545941

# Submission time Handle Problem Language Result Execution time Memory
545941 2022-04-05T16:15:44 Z rainboy Roads (CEOI20_roads) C
100 / 100
 183 ms 10384 KB 
#include <stdio.h>
#include <string.h>

#define N	100000

unsigned int X = 12345;

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

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

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 = xx[ii[j]] != xx[i_] ? xx[ii[j]] - xx[i_] : yy[ii[j]] - 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 zz[1 + N], ll[1 + N], rr[1 + N], kk[1 + N], u_, l_, r_;

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

	zz[_] = rand_(), kk[_] = k;
	return _++;
}

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 compare(int i, int j) {
	long long c1, c2;

	if (i == j)
		return 0;
	c1 = cross(xx[i << 1 | 0], yy[i << 1 | 0], xx[i << 1 | 1], yy[i << 1 | 1], xx[j << 1 | 0], yy[j << 1 | 0]);
	c2 = cross(xx[i << 1 | 0], yy[i << 1 | 0], xx[i << 1 | 1], yy[i << 1 | 1], xx[j << 1 | 1], yy[j << 1 | 1]);
	if (c1 != 0 && c2 != 0 && (c1 < 0) == (c2 < 0))
		return c1 < 0 ? -1 : 1;
	c1 = cross(xx[j << 1 | 0], yy[j << 1 | 0], xx[j << 1 | 1], yy[j << 1 | 1], xx[i << 1 | 0], yy[i << 1 | 0]);
	return c1 > 0 ? -1 : 1;
}

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

	if (u == 0) {
		u_ = l_ = r_ = 0;
		return;
	}
	c = compare(kk[u], k);
	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;
	}
}

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 main() {
	static int ii[N * 2], rep[N + 1];
	int n, h, i, tmp;

	scanf("%d", &n);
	for (i = 0; i < n * 2; i++)
		scanf("%d%d", &xx[i], &yy[i]);
	for (i = 0; i < n; i++)
		if (xx[i << 1 | 0] > xx[i << 1 | 1] || xx[i << 1 | 0] == xx[i << 1 | 1] && yy[i << 1 | 0] > yy[i << 1 | 1]) {
			tmp = xx[i << 1 | 0], xx[i << 1 | 0] = xx[i << 1 | 1], xx[i << 1 | 1] = tmp;
			tmp = yy[i << 1 | 0], yy[i << 1 | 0] = yy[i << 1 | 1], yy[i << 1 | 1] = tmp;
		}
	for (i = 0; i < n * 2; i++)
		ii[i] = i;
	sort(ii, 0, n * 2);
	memset(rep, -1, (n + 1) * sizeof *rep);
	for (h = 0; h < n * 2; h++) {
		int i_ = ii[h];

		i = i_ >> 1;
		if ((i_ & 1) == 0) {
			int p;

			split(u_, i);
			p = l_ ? kk[last(l_)] : n;
			if (rep[p] != -1) {
				printf("%d %d %d %d\n", xx[rep[p] << 1 | 1], yy[rep[p] << 1 | 1], xx[i_], yy[i_]);
				rep[p] = -1;
			}
			u_ = merge(merge(l_, node(i)), r_);
		} else {
			int p;

			split(u_, i);
			p = l_ ? kk[last(l_)] : n;
			if (rep[p] != -1) {
				printf("%d %d %d %d\n", xx[rep[p] << 1 | 1], yy[rep[p] << 1 | 1], xx[i_], yy[i_]);
				rep[p] = -1;
			}
			if (rep[i] != -1) {
				printf("%d %d %d %d\n", xx[rep[i] << 1 | 1], yy[rep[i] << 1 | 1], xx[i_], yy[i_]);
				rep[i] = -1;
			}
			rep[p] = i;
			u_ = merge(l_, r_);
		}
	}
	return 0;
}

Compilation message

roads.c: In function 'main':
roads.c:111:75: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  111 |   if (xx[i << 1 | 0] > xx[i << 1 | 1] || xx[i << 1 | 0] == xx[i << 1 | 1] && yy[i << 1 | 0] > yy[i << 1 | 1]) {
      |                                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
roads.c:107:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
roads.c:109:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |   scanf("%d%d", &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 59 ms 3760 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 292 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 2 ms 336 KB Output is correct
4 Correct 11 ms 1288 KB Output is correct
5 Correct 22 ms 2296 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 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 11 ms 1236 KB Output is correct
5 Correct 22 ms 2252 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 296 KB Output is correct
8 Correct 2 ms 432 KB Output is correct
9 Correct 12 ms 1216 KB Output is correct
10 Correct 164 ms 10316 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 292 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 2 ms 428 KB Output is correct
4 Correct 11 ms 1328 KB Output is correct
5 Correct 24 ms 2324 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 2 ms 340 KB Output is correct
9 Correct 11 ms 1236 KB Output is correct
10 Correct 57 ms 5332 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 1 ms 212 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 296 KB Output is correct
4 Correct 2 ms 340 KB Output is correct
5 Correct 12 ms 1332 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 304 KB Output is correct
8 Correct 2 ms 340 KB Output is correct
9 Correct 13 ms 1328 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 2 ms 340 KB Output is correct
13 Correct 12 ms 1220 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 296 KB Output is correct
16 Correct 1 ms 292 KB Output is correct
17 Correct 1 ms 212 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 2 ms 308 KB Output is correct
21 Correct 1 ms 292 KB Output is correct
22 Correct 6 ms 600 KB Output is correct
23 Correct 6 ms 652 KB Output is correct
24 Correct 12 ms 944 KB Output is correct
25 Correct 1 ms 288 KB Output is correct

Subtask #6
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 288 KB Output is correct
2 Correct 63 ms 3764 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 292 KB Output is correct
5 Correct 2 ms 340 KB Output is correct
6 Correct 12 ms 1236 KB Output is correct
7 Correct 24 ms 2308 KB Output is correct
8 Correct 1 ms 296 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 2 ms 340 KB Output is correct
11 Correct 14 ms 1244 KB Output is correct
12 Correct 183 ms 10384 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 2 ms 340 KB Output is correct
16 Correct 14 ms 1212 KB Output is correct
17 Correct 73 ms 5264 KB Output is correct
18 Correct 1 ms 212 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 312 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 1 ms 300 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 288 KB Output is correct
26 Correct 5 ms 596 KB Output is correct
27 Correct 6 ms 596 KB Output is correct
28 Correct 11 ms 984 KB Output is correct
29 Correct 114 ms 4660 KB Output is correct
30 Correct 105 ms 7540 KB Output is correct
31 Correct 2 ms 212 KB Output is correct
32 Correct 112 ms 7268 KB Output is correct
33 Correct 106 ms 7232 KB Output is correct
34 Correct 149 ms 9560 KB Output is correct
35 Correct 146 ms 9976 KB Output is correct
36 Correct 163 ms 7732 KB Output is correct