oj.uz

Submission #481428

# Submission time Handle Problem Language Result Execution time Memory
481428 2021-10-20T19:12:17 Z rainboy Matching (COCI20_matching) C
11 / 110
 0 ms 280 KB 
#include <stdio.h>
#include <string.h>

#define N	100000

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 *zz;

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)
			if (zz[ii[j]] == zz[i_])
				j++;
			else if (zz[ii[j]] < zz[i_]) {
				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 xx[N], yy[N];

int intersect_(int x1, int x2, int x3, int x4) {
	int tmp;

	if (x1 > x2)
		tmp = x1, x1 = x2, x2 = tmp;
	if (x3 > x4)
		tmp = x3, x3 = x4, x4 = tmp;
	return max(x1, x3) <= min(x2, x4);
}

int intersect(int i1, int j1, int i2, int j2) {
	return intersect_(xx[i1], xx[j1], xx[i2], xx[j2]) && intersect_(yy[i1], yy[j1], yy[i2], yy[j2]);
}

int ds[(N + 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 main() {
	static int ii[N], uu[N], vv[N], dd[N], cc[N + 1];
	int n, m, h, h_, i;

	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;
	zz = xx, sort(ii, 0, n);
	for (i = 0; i < n; i++)
		if (i + 1 < n && xx[ii[i]] == xx[ii[i + 1]]) {
			uu[m] = ii[i], vv[m] = ii[i + 1], m++;
			dd[ii[i]]++, dd[ii[i + 1]]++;
		}
	zz = yy, sort(ii, 0, n);
	for (i = 0; i < n; i++)
		if (i + 1 < n && yy[ii[i]] == yy[ii[i + 1]]) {
			uu[m] = ii[i], vv[m] = 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;
		}
	memset(ds, -1, (m + 1) * 2 * sizeof *ds);
	for (h = 0; h < m; h++)
		for (h_ = h + 1; h_ < m; h_++)
			if (intersect(uu[h], vv[h], uu[h_], vv[h_]))
				join(h << 1 | 0, h_ << 1 | 1), join(h << 1 | 1, h_ << 1 | 0);
	for (h = 0; h < m; h++)
		if (dd[uu[h]] == 1 || dd[vv[h]] == 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 | 0))
				cc[h] ^= 1;
	printf("DA\n");
	for (h = 0; h < m; h++)
		if (cc[h])
			printf("%d %d\n", uu[h] + 1, vv[h] + 1);
	return 0;
}

Compilation message

matching.c: In function 'main':
matching.c:76:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
matching.c:78:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |   scanf("%d%d", &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct

Subtask #2
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 280 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 280 KB Output is correct

Subtask #3
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 280 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 280 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Incorrect 0 ms 204 KB Unexpected end of file - int32 expected
10 Halted 0 ms 0 KB -

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 280 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 280 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Incorrect 0 ms 204 KB Unexpected end of file - int32 expected
10 Halted 0 ms 0 KB -

Subtask #5
0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 0 ms 280 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 280 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Incorrect 0 ms 204 KB Unexpected end of file - int32 expected
10 Halted 0 ms 0 KB -