Submission #926316

# Submission time Handle Problem Language Result Execution time Memory
926316 2024-02-12T19:18:32 Z rainboy ROI16_sending (ROI16_sending) C
63 / 100
197 ms 87636 KB
#include <stdio.h>
#include <stdlib.h>

#define N	200000
#define M	200000
#define L	19	/* L = ceil(log2(M * 2)) */
#define N_	(M * 2 * (L + 1) + 1)
#define INF	0x3f3f3f3f

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 *ej[N], eo[N], *eh[N], eo_[N], n;

void append(int **ej, int *eo, int i, int j) {
	int o = eo[i]++;

	if (o >= 2 && (o & o - 1) == 0)
		ej[i] = (int *) realloc(ej[i], o * 2 * sizeof *ej[i]);
	ej[i][o] = j;
}

int dd[N], pp[N], qq[N], ta[N], tb[N];

int dfs1(int i, int d) {
	int o, s, k_, j_;

	dd[i] = d;
	s = 1, k_ = 0, j_ = -1;
	for (o = eo[i]; o--; ) {
		int j = ej[i][o], k = dfs1(j, d + 1);

		s += k;
		if (k_ < k)
			k_ = k, j_ = j;
	}
	qq[i] = j_;
	return s;
}

void dfs2(int i, int q) {
	static int time;
	int o, j_;

	ta[i] = time++;
	j_ = qq[i], qq[i] = q;
	if (j_ != -1)
		dfs2(j_, q);
	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		if (j != j_)
			dfs2(j, j);
	}
	tb[i] = time;
}

int lca(int i, int j) {
	while (qq[i] != qq[j])
		if (dd[qq[i]] > dd[qq[j]])
			i = pp[qq[i]];
		else
			j = pp[qq[j]];
	return dd[i] < dd[j] ? i : j;
}

int ii[M * 2], idx[M * 2], m;

void sort(int *hh, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r, h = hh[l + rand_() % (r - l)], tmp;

		while (j < k) {
			int c = ta[ii[hh[j]]] - ta[ii[h]];

			if (c == 0)
				j++;
			else if (c < 0) {
				tmp = hh[i], hh[i] = hh[j], hh[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = hh[j], hh[j] = hh[k], hh[k] = tmp;
			}
		}
		sort(hh, l, i);
		l = k;
	}
}

int hh_[M * 2], dd1[M * 4], ddmn[M * 4];

void build(int l, int r) {
	int m;

	if (r - l == 1)
		ddmn[l + r] = INF;
	else {
		m = (l + r) / 2;
		build(l, m), build(m, r);
		ddmn[l + r] = min(min(ddmn[l + m], dd1[m]), ddmn[m + r]);
	}
}

int ll[N_], rr[N_], ddp[N_], ddq[N_], ddmx[N_];

int node(int l, int r, int i) {
	static int _ = 1;
	int t = _++;

	if (r - l == 1)
		ddp[t] = ddq[t] = INF, ddmx[t] = -1;
	else {
		int m = (l + r) / 2;

		if (i < m) {
			ll[t] = node(l, m, i);
			ddp[t] = ddp[ll[t]], ddq[t] = min(min(ddq[ll[t]], dd1[m]), ddmn[m + r]);
		} else {
			rr[t] = node(m, r, i);
			ddp[t] = min(min(ddmn[l + m], dd1[m]), ddp[rr[t]]), ddq[t] = ddq[rr[t]];
		}
		ddmx[t] = -1;
	}
	return t;
}

int remove_(int t, int l, int r, int i) {
	if (r - l == 1)
		t = 0;
	else {
		int m = (l + r) / 2;

		if (i < m)
			ll[t] = remove_(ll[t], l, m, i);
		else
			rr[t] = remove_(rr[t], m, r, i);
		if (ll[t] == 0 && rr[t] == 0)
			t = 0;
		else {
			ddp[t] = ll[t] ? ddp[ll[t]] : min(min(ddmn[l + m], dd1[m]), ddp[rr[t]]);
			ddq[t] = rr[t] ? ddq[rr[t]] : min(min(ddq[ll[t]], dd1[m]), ddmn[m + r]);
			ddmx[t] = max(max(ddmx[ll[t]], ddmx[rr[t]]), min(min(ddq[ll[t]], dd1[m]), ddp[rr[t]]));
		}
	}
	return t;
}

int merge(int t1, int t2, int l, int r) {
	int m;

	if (t1 == 0)
		return t2;
	if (t2 == 0)
		return t1;
	m = (l + r) / 2;
	ll[t1] = merge(ll[t1], ll[t2], l, m), rr[t1] = merge(rr[t1], rr[t2], m, r);
	ddp[t1] = ll[t1] ? ddp[ll[t1]] : min(min(ddmn[l + m], dd1[m]), ddp[rr[t1]]);
	ddq[t1] = rr[t1] ? ddq[rr[t1]] : min(min(ddq[ll[t1]], dd1[m]), ddmn[m + r]);
	ddmx[t1] = max(max(ddmx[ll[t1]], ddmx[rr[t1]]), min(min(ddq[ll[t1]], dd1[m]), ddp[rr[t1]]));
	return t1;
}

int find_p(int t, int l, int r) {
	int m;

	if (r - l == 1)
		return hh_[l] >> 1;
	m = (l + r) / 2;
	return ll[t] ? find_p(ll[t], l, m) : find_p(rr[t], m, r);
}

int find_q(int t, int l, int r) {
	int m;

	if (r - l == 1)
		return hh_[l] >> 1;
	m = (l + r) / 2;
	return rr[t] ? find_q(rr[t], m, r) : find_q(ll[t], l, m);
}

void find_mx(int t, int l, int r, int *h1, int *h2) {
	int m;

	m = (l + r) / 2;
	if (ddmx[ll[t]] == ddmx[t])
		find_mx(ll[t], l, m, h1, h2);
	else if (ddmx[rr[t]] == ddmx[t])
		find_mx(rr[t], m, r, h1, h2);
	else
		*h1 = find_q(ll[t], l, m), *h2 = find_p(rr[t], m, r);
}

int t_, d_, h1_, h2_;

void dfs3(int i) {
	static int hh[M * 2], tt[M * 2], dd1[M * 2];
	int m_, cnt, h, o, d, d1;

	if (eo_[i]) {
		m_ = 0;
		for (o = eo_[i]; o--; ) {
			h = eh[i][o];
			hh[m_++] = h << 1 | 0, hh[m_++] = h << 1 | 1;
		}
		sort(hh, 0, m_);
		cnt = 0;
		for (h = 0; h <= m_; h++) {
			d1 = h == 0 || h == m_ ? -1 : dd[lca(ii[hh[h]], ii[hh[h - 1]])];
			while (cnt >= 2 && dd1[cnt - 1] >= d1) {
				tt[cnt - 2] = merge(tt[cnt - 2], tt[cnt - 1], 0, m * 2);
				if (ddmx[tt[cnt - 2]] != -1) {
					d = dd1[cnt - 1] + ddmx[tt[cnt - 2]] - dd[i] * 2;
					if (d_ < d)
						d_ = d, find_mx(tt[cnt - 2], 0, m * 2, &h1_, &h2_);
				}
				cnt--;
			}
			if (h < m_)
				tt[cnt] = node(0, m * 2, idx[hh[h] ^ 1]), dd1[cnt] = d1, cnt++;
		}
		t_ = merge(t_, tt[0], 0, m * 2);
	}
	if (ddmx[t_] != -1) {
		d = ddmx[t_] - dd[i];
		if (d_ < d)
			d_ = d, find_mx(t_, 0, m * 2, &h1_, &h2_);
	}
	for (o = eo[i]; o--; ) {
		int j = ej[i][o];

		dfs3(j);
	}
	for (o = eo_[i]; o--; ) {
		h = eh[i][o];
		t_ = remove_(t_, 0, m * 2, idx[h << 1 | 0]);
		t_ = remove_(t_, 0, m * 2, idx[h << 1 | 1]);
	}
}

int main() {
	int h, i, j;

	scanf("%d%d", &n, &m);
	for (i = 0; i < n; i++)
		ej[i] = (int *) malloc(2 * sizeof *ej[i]);
	for (i = 1; i < n; i++) {
		scanf("%d", &pp[i]), pp[i]--;
		append(ej, eo, pp[i], i);
	}
	dfs1(0, 0);
	dfs2(0, 0);
	for (i = 0; i < n; i++)
		eh[i] = (int *) malloc(2 * sizeof *eh[i]);
	for (h = 0; h < m; h++) {
		scanf("%d%d", &i, &j), i--, j--;
		ii[h << 1 | 0] = i, ii[h << 1 | 1] = j;
		append(eh, eo_, lca(i, j), h);
	}
	for (h = 0; h < m * 2; h++)
		hh_[h] = h;
	sort(hh_, 0, m * 2);
	for (h = 0; h < m * 2; h++)
		idx[hh_[h]] = h;
	for (h = 1; h < m * 2; h++)
		dd1[h] = dd[lca(ii[hh_[h - 1]], ii[hh_[h]])];
	build(0, m * 2);
	ddmx[0] = -1;
	d_ = 0, h1_ = 0, h2_ = 1, dfs3(0);
	printf("%d\n", d_);
	printf("%d %d\n", h1_ + 1, h2_ + 1);
	return 0;
}

Compilation message

sending.c: In function 'append':
sending.c:24:23: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   24 |  if (o >= 2 && (o & o - 1) == 0)
      |                     ~~^~~
sending.c: In function 'main':
sending.c:250:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  250 |  scanf("%d%d", &n, &m);
      |  ^~~~~~~~~~~~~~~~~~~~~
sending.c:254:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  254 |   scanf("%d", &pp[i]), pp[i]--;
      |   ^~~~~~~~~~~~~~~~~~~
sending.c:262:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  262 |   scanf("%d%d", &i, &j), i--, j--;
      |   ^~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 6 ms 31068 KB Output is correct
2 Correct 4 ms 31068 KB Output is correct
3 Correct 4 ms 31068 KB Output is correct
4 Correct 4 ms 31068 KB Output is correct
5 Correct 3 ms 31068 KB Output is correct
6 Correct 4 ms 31064 KB Output is correct
7 Correct 3 ms 31068 KB Output is correct
8 Correct 4 ms 31064 KB Output is correct
9 Correct 3 ms 31068 KB Output is correct
10 Correct 4 ms 31068 KB Output is correct
11 Correct 4 ms 31068 KB Output is correct
12 Correct 4 ms 31064 KB Output is correct
13 Correct 3 ms 31068 KB Output is correct
14 Correct 3 ms 31068 KB Output is correct
15 Correct 4 ms 31064 KB Output is correct
16 Correct 4 ms 31068 KB Output is correct
17 Correct 3 ms 31068 KB Output is correct
18 Correct 3 ms 31068 KB Output is correct
19 Correct 4 ms 31068 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 6 ms 31068 KB Output is correct
2 Correct 4 ms 31068 KB Output is correct
3 Correct 4 ms 31068 KB Output is correct
4 Correct 4 ms 31068 KB Output is correct
5 Correct 3 ms 31068 KB Output is correct
6 Correct 4 ms 31064 KB Output is correct
7 Correct 3 ms 31068 KB Output is correct
8 Correct 4 ms 31064 KB Output is correct
9 Correct 3 ms 31068 KB Output is correct
10 Correct 4 ms 31068 KB Output is correct
11 Correct 4 ms 31068 KB Output is correct
12 Correct 4 ms 31064 KB Output is correct
13 Correct 3 ms 31068 KB Output is correct
14 Correct 3 ms 31068 KB Output is correct
15 Correct 4 ms 31064 KB Output is correct
16 Correct 4 ms 31068 KB Output is correct
17 Correct 3 ms 31068 KB Output is correct
18 Correct 3 ms 31068 KB Output is correct
19 Correct 4 ms 31068 KB Output is correct
20 Correct 6 ms 33372 KB Output is correct
21 Correct 6 ms 33372 KB Output is correct
22 Correct 5 ms 33884 KB Output is correct
23 Correct 5 ms 33696 KB Output is correct
24 Correct 6 ms 33612 KB Output is correct
25 Correct 6 ms 33628 KB Output is correct
26 Correct 6 ms 33824 KB Output is correct
27 Correct 6 ms 33628 KB Output is correct
28 Correct 6 ms 33628 KB Output is correct
29 Correct 5 ms 33884 KB Output is correct
30 Correct 6 ms 31932 KB Output is correct
31 Correct 5 ms 31836 KB Output is correct
32 Correct 5 ms 33868 KB Output is correct
33 Correct 6 ms 33628 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 6 ms 31068 KB Output is correct
2 Correct 4 ms 31068 KB Output is correct
3 Correct 4 ms 31068 KB Output is correct
4 Correct 4 ms 31068 KB Output is correct
5 Correct 3 ms 31068 KB Output is correct
6 Correct 4 ms 31064 KB Output is correct
7 Correct 3 ms 31068 KB Output is correct
8 Correct 4 ms 31064 KB Output is correct
9 Correct 3 ms 31068 KB Output is correct
10 Correct 4 ms 31068 KB Output is correct
11 Correct 4 ms 31068 KB Output is correct
12 Correct 4 ms 31064 KB Output is correct
13 Correct 3 ms 31068 KB Output is correct
14 Correct 3 ms 31068 KB Output is correct
15 Correct 4 ms 31064 KB Output is correct
16 Correct 4 ms 31068 KB Output is correct
17 Correct 3 ms 31068 KB Output is correct
18 Correct 3 ms 31068 KB Output is correct
19 Correct 4 ms 31068 KB Output is correct
20 Correct 6 ms 33372 KB Output is correct
21 Correct 6 ms 33372 KB Output is correct
22 Correct 5 ms 33884 KB Output is correct
23 Correct 5 ms 33696 KB Output is correct
24 Correct 6 ms 33612 KB Output is correct
25 Correct 6 ms 33628 KB Output is correct
26 Correct 6 ms 33824 KB Output is correct
27 Correct 6 ms 33628 KB Output is correct
28 Correct 6 ms 33628 KB Output is correct
29 Correct 5 ms 33884 KB Output is correct
30 Correct 6 ms 31932 KB Output is correct
31 Correct 5 ms 31836 KB Output is correct
32 Correct 5 ms 33868 KB Output is correct
33 Correct 6 ms 33628 KB Output is correct
34 Correct 30 ms 40020 KB Output is correct
35 Correct 30 ms 40116 KB Output is correct
36 Correct 29 ms 51036 KB Output is correct
37 Correct 29 ms 45532 KB Output is correct
38 Correct 34 ms 45540 KB Output is correct
39 Correct 17 ms 40024 KB Output is correct
40 Correct 29 ms 51028 KB Output is correct
41 Correct 22 ms 40608 KB Output is correct
42 Correct 19 ms 40028 KB Output is correct
43 Correct 26 ms 50012 KB Output is correct
44 Correct 30 ms 47696 KB Output is correct
45 Correct 27 ms 47868 KB Output is correct
46 Incorrect 26 ms 50000 KB Output isn't correct
47 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 6 ms 31068 KB Output is correct
2 Correct 4 ms 31068 KB Output is correct
3 Correct 4 ms 31068 KB Output is correct
4 Correct 4 ms 31068 KB Output is correct
5 Correct 3 ms 31068 KB Output is correct
6 Correct 4 ms 31064 KB Output is correct
7 Correct 3 ms 31068 KB Output is correct
8 Correct 4 ms 31064 KB Output is correct
9 Correct 3 ms 31068 KB Output is correct
10 Correct 4 ms 31068 KB Output is correct
11 Correct 4 ms 31068 KB Output is correct
12 Correct 4 ms 31064 KB Output is correct
13 Correct 3 ms 31068 KB Output is correct
14 Correct 3 ms 31068 KB Output is correct
15 Correct 4 ms 31064 KB Output is correct
16 Correct 4 ms 31068 KB Output is correct
17 Correct 3 ms 31068 KB Output is correct
18 Correct 3 ms 31068 KB Output is correct
19 Correct 4 ms 31068 KB Output is correct
20 Correct 6 ms 33372 KB Output is correct
21 Correct 6 ms 33372 KB Output is correct
22 Correct 5 ms 33884 KB Output is correct
23 Correct 5 ms 33696 KB Output is correct
24 Correct 6 ms 33612 KB Output is correct
25 Correct 6 ms 33628 KB Output is correct
26 Correct 6 ms 33824 KB Output is correct
27 Correct 6 ms 33628 KB Output is correct
28 Correct 6 ms 33628 KB Output is correct
29 Correct 5 ms 33884 KB Output is correct
30 Correct 6 ms 31932 KB Output is correct
31 Correct 5 ms 31836 KB Output is correct
32 Correct 5 ms 33868 KB Output is correct
33 Correct 6 ms 33628 KB Output is correct
34 Correct 30 ms 40020 KB Output is correct
35 Correct 30 ms 40116 KB Output is correct
36 Correct 29 ms 51036 KB Output is correct
37 Correct 29 ms 45532 KB Output is correct
38 Correct 34 ms 45540 KB Output is correct
39 Correct 17 ms 40024 KB Output is correct
40 Correct 29 ms 51028 KB Output is correct
41 Correct 22 ms 40608 KB Output is correct
42 Correct 19 ms 40028 KB Output is correct
43 Correct 26 ms 50012 KB Output is correct
44 Correct 30 ms 47696 KB Output is correct
45 Correct 27 ms 47868 KB Output is correct
46 Incorrect 26 ms 50000 KB Output isn't correct
47 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 129 ms 75856 KB Output is correct
2 Correct 174 ms 75752 KB Output is correct
3 Correct 186 ms 76080 KB Output is correct
4 Correct 172 ms 76120 KB Output is correct
5 Correct 143 ms 75604 KB Output is correct
6 Correct 197 ms 75864 KB Output is correct
7 Correct 175 ms 76976 KB Output is correct
8 Correct 175 ms 77016 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 131 ms 75764 KB Output is correct
2 Correct 127 ms 75572 KB Output is correct
3 Correct 151 ms 86488 KB Output is correct
4 Correct 134 ms 80980 KB Output is correct
5 Correct 136 ms 80836 KB Output is correct
6 Correct 138 ms 76116 KB Output is correct
7 Correct 148 ms 87636 KB Output is correct
8 Correct 108 ms 77164 KB Output is correct
9 Correct 107 ms 76608 KB Output is correct
10 Correct 91 ms 87636 KB Output is correct
11 Correct 56 ms 68688 KB Output is correct
12 Correct 62 ms 68872 KB Output is correct
13 Correct 147 ms 87544 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 6 ms 31068 KB Output is correct
2 Correct 4 ms 31068 KB Output is correct
3 Correct 4 ms 31068 KB Output is correct
4 Correct 4 ms 31068 KB Output is correct
5 Correct 3 ms 31068 KB Output is correct
6 Correct 4 ms 31064 KB Output is correct
7 Correct 3 ms 31068 KB Output is correct
8 Correct 4 ms 31064 KB Output is correct
9 Correct 3 ms 31068 KB Output is correct
10 Correct 4 ms 31068 KB Output is correct
11 Correct 4 ms 31068 KB Output is correct
12 Correct 4 ms 31064 KB Output is correct
13 Correct 3 ms 31068 KB Output is correct
14 Correct 3 ms 31068 KB Output is correct
15 Correct 4 ms 31064 KB Output is correct
16 Correct 4 ms 31068 KB Output is correct
17 Correct 3 ms 31068 KB Output is correct
18 Correct 3 ms 31068 KB Output is correct
19 Correct 4 ms 31068 KB Output is correct
20 Correct 6 ms 33372 KB Output is correct
21 Correct 6 ms 33372 KB Output is correct
22 Correct 5 ms 33884 KB Output is correct
23 Correct 5 ms 33696 KB Output is correct
24 Correct 6 ms 33612 KB Output is correct
25 Correct 6 ms 33628 KB Output is correct
26 Correct 6 ms 33824 KB Output is correct
27 Correct 6 ms 33628 KB Output is correct
28 Correct 6 ms 33628 KB Output is correct
29 Correct 5 ms 33884 KB Output is correct
30 Correct 6 ms 31932 KB Output is correct
31 Correct 5 ms 31836 KB Output is correct
32 Correct 5 ms 33868 KB Output is correct
33 Correct 6 ms 33628 KB Output is correct
34 Correct 30 ms 40020 KB Output is correct
35 Correct 30 ms 40116 KB Output is correct
36 Correct 29 ms 51036 KB Output is correct
37 Correct 29 ms 45532 KB Output is correct
38 Correct 34 ms 45540 KB Output is correct
39 Correct 17 ms 40024 KB Output is correct
40 Correct 29 ms 51028 KB Output is correct
41 Correct 22 ms 40608 KB Output is correct
42 Correct 19 ms 40028 KB Output is correct
43 Correct 26 ms 50012 KB Output is correct
44 Correct 30 ms 47696 KB Output is correct
45 Correct 27 ms 47868 KB Output is correct
46 Incorrect 26 ms 50000 KB Output isn't correct
47 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 6 ms 31068 KB Output is correct
2 Correct 4 ms 31068 KB Output is correct
3 Correct 4 ms 31068 KB Output is correct
4 Correct 4 ms 31068 KB Output is correct
5 Correct 3 ms 31068 KB Output is correct
6 Correct 4 ms 31064 KB Output is correct
7 Correct 3 ms 31068 KB Output is correct
8 Correct 4 ms 31064 KB Output is correct
9 Correct 3 ms 31068 KB Output is correct
10 Correct 4 ms 31068 KB Output is correct
11 Correct 4 ms 31068 KB Output is correct
12 Correct 4 ms 31064 KB Output is correct
13 Correct 3 ms 31068 KB Output is correct
14 Correct 3 ms 31068 KB Output is correct
15 Correct 4 ms 31064 KB Output is correct
16 Correct 4 ms 31068 KB Output is correct
17 Correct 3 ms 31068 KB Output is correct
18 Correct 3 ms 31068 KB Output is correct
19 Correct 4 ms 31068 KB Output is correct
20 Correct 6 ms 33372 KB Output is correct
21 Correct 6 ms 33372 KB Output is correct
22 Correct 5 ms 33884 KB Output is correct
23 Correct 5 ms 33696 KB Output is correct
24 Correct 6 ms 33612 KB Output is correct
25 Correct 6 ms 33628 KB Output is correct
26 Correct 6 ms 33824 KB Output is correct
27 Correct 6 ms 33628 KB Output is correct
28 Correct 6 ms 33628 KB Output is correct
29 Correct 5 ms 33884 KB Output is correct
30 Correct 6 ms 31932 KB Output is correct
31 Correct 5 ms 31836 KB Output is correct
32 Correct 5 ms 33868 KB Output is correct
33 Correct 6 ms 33628 KB Output is correct
34 Correct 30 ms 40020 KB Output is correct
35 Correct 30 ms 40116 KB Output is correct
36 Correct 29 ms 51036 KB Output is correct
37 Correct 29 ms 45532 KB Output is correct
38 Correct 34 ms 45540 KB Output is correct
39 Correct 17 ms 40024 KB Output is correct
40 Correct 29 ms 51028 KB Output is correct
41 Correct 22 ms 40608 KB Output is correct
42 Correct 19 ms 40028 KB Output is correct
43 Correct 26 ms 50012 KB Output is correct
44 Correct 30 ms 47696 KB Output is correct
45 Correct 27 ms 47868 KB Output is correct
46 Incorrect 26 ms 50000 KB Output isn't correct
47 Halted 0 ms 0 KB -