oj.uz

Submission #481714

# Submission time Handle Problem Language Result Execution time Memory
481714 2021-10-21T13:00:27 Z rainboy Matching (COCI20_matching) C
110 / 110
 219 ms 8332 KB 
#include <stdio.h>
#include <string.h>

#define N	100000
#define M	N

int min(int a, int b) { return a < b ? a : b; }
int max(int a, int b) { return a > b ? a : b; }

unsigned int X = 12345;

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

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

int compare_x(int i, int j) { return xx[i] - xx[j]; }
int compare_y(int i, int j) { return yy[i] - yy[j]; }
int compare_z(int h1, int h2) {
	return yy[ii_[h1]] != yy[ii_[h2]] ? yy[ii_[h1]] - yy[ii_[h2]] : yy[ii_[h2 ^ 1]] - yy[ii_[h1 ^ 1]];
}

int (*compare)(int, int);

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(ii[j], 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 ds[(M + 1) * 2];

int find(int i) {
	return ds[i] < 0 ? i : (ds[i] = find(ds[i]));
}

void join(int i, int j) {
	i = find(i);
	j = find(j);
	if (i == j)
		return;
	if (ds[i] > ds[j])
		ds[i] = j;
	else {
		if (ds[i] == ds[j])
			ds[i]--;
		ds[j] = i;
	}
}

int zz[1 + M * 4], ll[1 + M * 4], rr[1 + M * 4], hh[1 + M * 4], u_, l_, r_;

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

	zz[_] = rand_();
	hh[_] = h;
	return _++;
}

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

	if (u == 0) {
		u_ = l_ = r_ = 0;
		return;
	}
	c = xx[ii_[hh[u] << 1 | 0]] - xx[ii_[h << 1 | 0]];
	if (c < 0) {
		split(rr[u], h);
		rr[u] = l_, l_ = u;
	} else if (c > 0) {
		split(ll[u], h);
		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 == 0 ? -1 : hh[u]) : first(ll[u]); }
int last(int u) { return rr[u] == 0 ? (u == 0 ? -1 : hh[u]) : last(rr[u]); }

int tr_higher(int u, int x) {
	int h = -1;

	while (u)
		if (xx[ii_[hh[u] << 1 | 0]] > x)
			h = hh[u], u = ll[u];
		else
			u = rr[u];
	return h;
}

int main() {
	static int ii[N], dd[N], cc[M + 1], hh[M * 2], qq[M];
	int n, m, h, i, u1, u2;

	scanf("%d", &n);
	for (i = 0; i < n; i++)
		scanf("%d%d", &xx[i], &yy[i]);
	for (i = 0; i < n; i++)
		ii[i] = i;
	m = 0;
	compare = compare_x, sort(ii, 0, n);
	for (i = 0; i < n; i++)
		if (i + 1 < n && xx[ii[i]] == xx[ii[i + 1]]) {
			ii_[m << 1 | 0] = ii[i], ii_[m << 1 | 1] = ii[i + 1], m++;
			dd[ii[i]]++, dd[ii[i + 1]]++;
		}
	compare = compare_y, sort(ii, 0, n);
	for (i = 0; i < n; i++)
		if (i + 1 < n && yy[ii[i]] == yy[ii[i + 1]]) {
			ii_[m << 1 | 0] = ii[i], ii_[m << 1 | 1] = ii[i + 1], m++;
			dd[ii[i]]++, dd[ii[i + 1]]++;
		}
	for (i = 0; i < n; i++)
		if (dd[i] == 0) {
			printf("NE\n");
			return 0;
		}
	for (h = 0; h < m * 2; h++)
		hh[h] = h;
	compare = compare_z, sort(hh, 0, m * 2);
	memset(ds, -1, (m + 1) * 2 * sizeof *ds);
	u1 = u2 = 0;
	for (h = 0; h < m * 2; h++) {
		int h_ = hh[h], h1 = h_ >> 1, p, q;

		if (yy[ii_[h_]] < yy[ii_[h_ ^ 1]]) {
			split(u1, h1), p = last(l_), q = first(r_), u1 = merge(merge(l_, node(h1)), r_);
			if (p != -1 && q != -1)
				split(u2, p), u2 = merge(l_, r_);
			if (p != -1)
				split(u2, p), u2 = merge(merge(l_, node(p)), r_);
			if (q != -1)
				split(u2, h1), u2 = merge(merge(l_, node(h1)), r_);
			qq[h1] = q;
			if (p != -1)
				qq[p] = h1;
		} else if (yy[ii_[h_]] > yy[ii_[h_ ^ 1]]) {
			split(u1, h1), p = last(l_), q = first(r_), u1 = merge(l_, r_);
			if (p != -1)
				split(u2, p), u2 = merge(l_, r_);
			if (q != -1)
				split(u2, h1), u2 = merge(l_, r_);
			if (p != -1 && q != -1)
				split(u2, p), u2 = merge(merge(l_, node(p)), r_);
			if (p != -1)
				qq[p] = q;
		} else if (xx[ii_[h_]] < xx[ii_[h_ ^ 1]]) {
			int l = xx[ii_[h_]], r = xx[ii_[h_ ^ 1]], h2, h3;

			h2 = tr_higher(u1, l - 1);
			if (h2 != -1 && xx[ii_[h2 << 1 | 0]] <= r) {
				join(h1 << 1 | 0, h2 << 1 | 1), join(h1 << 1 | 1, h2 << 1 | 0);
				while (1) {
					h2 = tr_higher(u2, l - 1);
					if (h2 == -1)
						break;
					h3 = qq[h2];
					if (xx[ii_[h3 << 1 | 0]] > r)
						break;
					join(h2 << 1 | 0, h3 << 1 | 0), join(h2 << 1 | 1, h3 << 1 | 1);
					split(u2, h2), u2 = merge(l_, r_);
				}
			}
		}
	}
	for (h = 0; h < m; h++)
		if (dd[ii_[h << 1 | 0]] == 1 || dd[ii_[h << 1 | 1]] == 1)
			join(h << 1 | 0, m << 1 | 1), join(h << 1 | 1, m << 1 | 0);
	for (h = 0; h < m; h++)
		if (find(h << 1 | 0) == find(h << 1 | 1)) {
			printf("NE\n");
			return 0;
		}
	for (h = 0; h <= m; h++)
		cc[h] = find(h << 1 | 0) < find(h << 1 | 1);
	if (cc[m])
		for (h = 0; h <= m; h++)
			if (find(h << 1 | 0) == find(m << 1 | 0) || find(h << 1 | 0) == find(m << 1 | 1))
				cc[h] ^= 1;
	printf("DA\n");
	for (h = 0; h < m; h++)
		if (cc[h])
			printf("%d %d\n", ii_[h << 1 | 0] + 1, ii_[h << 1 | 1] + 1);
	return 0;
}

Compilation message

matching.c: In function 'main':
matching.c:131:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  131 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
matching.c:133:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  133 |   scanf("%d%d", &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 0 ms 332 KB Output is correct

Subtask #2
6.0 / 6.0

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

Subtask #3
7.0 / 7.0

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

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 0 ms 332 KB Output is correct
5 Correct 0 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 0 ms 332 KB Output is correct
9 Correct 0 ms 332 KB Output is correct
10 Correct 0 ms 332 KB Output is correct
11 Correct 0 ms 332 KB Output is correct
12 Correct 0 ms 332 KB Output is correct
13 Correct 2 ms 460 KB Output is correct
14 Correct 2 ms 460 KB Output is correct
15 Correct 3 ms 460 KB Output is correct
16 Correct 2 ms 460 KB Output is correct
17 Correct 2 ms 460 KB Output is correct
18 Correct 2 ms 460 KB Output is correct
19 Correct 2 ms 460 KB Output is correct
20 Correct 2 ms 460 KB Output is correct
21 Correct 2 ms 460 KB Output is correct
22 Correct 3 ms 460 KB Output is correct
23 Correct 2 ms 460 KB Output is correct
24 Correct 2 ms 460 KB Output is correct

Subtask #5
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 0 ms 332 KB Output is correct
5 Correct 0 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 0 ms 332 KB Output is correct
9 Correct 0 ms 332 KB Output is correct
10 Correct 0 ms 332 KB Output is correct
11 Correct 0 ms 332 KB Output is correct
12 Correct 0 ms 332 KB Output is correct
13 Correct 2 ms 460 KB Output is correct
14 Correct 2 ms 460 KB Output is correct
15 Correct 3 ms 460 KB Output is correct
16 Correct 2 ms 460 KB Output is correct
17 Correct 2 ms 460 KB Output is correct
18 Correct 2 ms 460 KB Output is correct
19 Correct 2 ms 460 KB Output is correct
20 Correct 2 ms 460 KB Output is correct
21 Correct 2 ms 460 KB Output is correct
22 Correct 3 ms 460 KB Output is correct
23 Correct 2 ms 460 KB Output is correct
24 Correct 2 ms 460 KB Output is correct
25 Correct 120 ms 8256 KB Output is correct
26 Correct 130 ms 8332 KB Output is correct
27 Correct 124 ms 8328 KB Output is correct
28 Correct 121 ms 8308 KB Output is correct
29 Correct 112 ms 7236 KB Output is correct
30 Correct 117 ms 7252 KB Output is correct
31 Correct 112 ms 7236 KB Output is correct
32 Correct 113 ms 7332 KB Output is correct
33 Correct 99 ms 6604 KB Output is correct
34 Correct 103 ms 6628 KB Output is correct
35 Correct 37 ms 2372 KB Output is correct
36 Correct 219 ms 7620 KB Output is correct
37 Correct 97 ms 7996 KB Output is correct
38 Correct 93 ms 7040 KB Output is correct