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Submission #828383

# Submission time Handle Problem Language Result Execution time Memory
828383 2023-08-17T09:04:41 Z serifefedartar Cat in a tree (BOI17_catinatree) C++17
51 / 100
 1000 ms 32536 KB 
#include <bits/stdc++.h>
using namespace std;
 
#define fast ios::sync_with_stdio(0);cin.tie(0);
typedef long long ll;
#define f first
#define s second
#define MOD 998244353
#define LOGN 18
#define MAXN 200005

vector<int> graph[MAXN];
vector<int> par, sz, nearest;
int up[LOGN][MAXN], depth[MAXN];
bool marked[MAXN];

void dfs(int node, int parent) {
	for (auto u : graph[node]) {
		if (u == parent)
			continue;
		depth[u] = depth[node] + 1;
		up[0][u] = node;
		for (int i = 1; i < LOGN; i++)
			up[i][u] = up[i-1][up[i-1][u]];
		dfs(u, node);
	}
}

int find(int node, int k) {
	for (int i = 0; i < LOGN; i++) {
		if ((1<<i) & k)
			node = up[i][node];
	}
	return node;
}

int lca(int a, int b) {
	if (depth[b] > depth[a])
		swap(a, b);
	a = find(a, depth[a] - depth[b]);
	if (a == b)
		return a;
	for (int i = LOGN-1; i >= 0; i--) {
		if (up[i][a] != up[i][b]) {
			a = up[i][a];
			b = up[i][b];
		}
	}
	return up[0][a];
}

int dist(int a, int b) {
	return depth[a] + depth[b] - 2*depth[lca(a, b)];
}
	
int get_sz(int node, int parent) {
	for (auto u : graph[node]) {
		if (u == parent || marked[u])
			continue;
		sz[node] += get_sz(u, node);
	}
	return sz[node];
}

int find_centro(int node, int parent, int n) {
	for (auto u : graph[node]) {
		if (u == parent || marked[u])
			continue;
		if (sz[u] * 2 > n)
			return find_centro(u, node, n);
	}
	return node;
}

void decompose(int node, int parent) {
	int n = get_sz(node, parent);
	int centro = find_centro(node, node, n);

	par[centro] = parent;
	marked[centro] = true;
	for (auto u : graph[centro]) {
		if (!marked[u])
			decompose(u, centro);
	}
}

int main() {
	int N, D;
	cin >> N >> D;

	nearest = vector<int>(N, 1e9);
	par = vector<int>(N, -1);
	sz = vector<int>(N, 1);
	for (int i = 1; i < N; i++) {
		int x; cin >> x;
		graph[x].push_back(i);
		graph[i].push_back(x);
	}
	for (int i = 0; i < LOGN; i++)
		up[i][0] = 0;
	dfs(0, 0);
	decompose(0, -1);

	vector<pair<int,int>> order;
	for (int i = 0; i < N; i++)
		order.push_back({depth[i], i});
	sort(order.rbegin(), order.rend());

	int ans = 0;
	for (auto u : order) {
		int node = u.s;
		int now = node;
		int mn_dist = 1e9;
		while (now != -1) {
			mn_dist = min(mn_dist, dist(node, now) + nearest[now]);
			now = par[now];
		}

		if (mn_dist >= D) {
			ans++;
			int now = node;
			while (now != -1) {
				nearest[now] = min(nearest[now], dist(node, now));
				now = par[now];
			}
		}
	}
	cout << ans << "\n";
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5076 KB Output is correct
2 Correct 3 ms 5008 KB Output is correct
3 Correct 3 ms 5076 KB Output is correct
4 Correct 3 ms 5076 KB Output is correct
5 Correct 3 ms 5076 KB Output is correct
6 Correct 3 ms 5076 KB Output is correct
7 Correct 2 ms 5076 KB Output is correct
8 Correct 3 ms 5076 KB Output is correct
9 Correct 3 ms 5076 KB Output is correct
10 Correct 2 ms 5004 KB Output is correct
11 Correct 3 ms 5004 KB Output is correct
12 Correct 2 ms 5076 KB Output is correct
13 Correct 3 ms 5076 KB Output is correct
14 Correct 3 ms 5076 KB Output is correct
15 Correct 2 ms 5004 KB Output is correct
16 Correct 3 ms 5076 KB Output is correct
17 Correct 3 ms 5076 KB Output is correct
18 Correct 3 ms 5076 KB Output is correct
19 Correct 3 ms 5112 KB Output is correct
20 Correct 3 ms 5076 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5076 KB Output is correct
2 Correct 3 ms 5008 KB Output is correct
3 Correct 3 ms 5076 KB Output is correct
4 Correct 3 ms 5076 KB Output is correct
5 Correct 3 ms 5076 KB Output is correct
6 Correct 3 ms 5076 KB Output is correct
7 Correct 2 ms 5076 KB Output is correct
8 Correct 3 ms 5076 KB Output is correct
9 Correct 3 ms 5076 KB Output is correct
10 Correct 2 ms 5004 KB Output is correct
11 Correct 3 ms 5004 KB Output is correct
12 Correct 2 ms 5076 KB Output is correct
13 Correct 3 ms 5076 KB Output is correct
14 Correct 3 ms 5076 KB Output is correct
15 Correct 2 ms 5004 KB Output is correct
16 Correct 3 ms 5076 KB Output is correct
17 Correct 3 ms 5076 KB Output is correct
18 Correct 3 ms 5076 KB Output is correct
19 Correct 3 ms 5112 KB Output is correct
20 Correct 3 ms 5076 KB Output is correct
21 Correct 6 ms 5392 KB Output is correct
22 Correct 3 ms 5076 KB Output is correct
23 Correct 3 ms 5076 KB Output is correct
24 Correct 2 ms 5076 KB Output is correct
25 Correct 3 ms 5136 KB Output is correct
26 Correct 3 ms 5204 KB Output is correct
27 Correct 3 ms 5204 KB Output is correct
28 Correct 3 ms 5204 KB Output is correct
29 Correct 5 ms 5268 KB Output is correct
30 Correct 5 ms 5240 KB Output is correct
31 Correct 3 ms 5204 KB Output is correct
32 Correct 3 ms 5204 KB Output is correct
33 Correct 3 ms 5204 KB Output is correct
34 Correct 4 ms 5204 KB Output is correct
35 Correct 4 ms 5204 KB Output is correct
36 Correct 4 ms 5264 KB Output is correct
37 Correct 3 ms 5268 KB Output is correct
38 Correct 4 ms 5332 KB Output is correct
39 Correct 4 ms 5332 KB Output is correct
40 Correct 6 ms 5332 KB Output is correct

Subtask #3
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5076 KB Output is correct
2 Correct 3 ms 5008 KB Output is correct
3 Correct 3 ms 5076 KB Output is correct
4 Correct 3 ms 5076 KB Output is correct
5 Correct 3 ms 5076 KB Output is correct
6 Correct 3 ms 5076 KB Output is correct
7 Correct 2 ms 5076 KB Output is correct
8 Correct 3 ms 5076 KB Output is correct
9 Correct 3 ms 5076 KB Output is correct
10 Correct 2 ms 5004 KB Output is correct
11 Correct 3 ms 5004 KB Output is correct
12 Correct 2 ms 5076 KB Output is correct
13 Correct 3 ms 5076 KB Output is correct
14 Correct 3 ms 5076 KB Output is correct
15 Correct 2 ms 5004 KB Output is correct
16 Correct 3 ms 5076 KB Output is correct
17 Correct 3 ms 5076 KB Output is correct
18 Correct 3 ms 5076 KB Output is correct
19 Correct 3 ms 5112 KB Output is correct
20 Correct 3 ms 5076 KB Output is correct
21 Correct 6 ms 5392 KB Output is correct
22 Correct 3 ms 5076 KB Output is correct
23 Correct 3 ms 5076 KB Output is correct
24 Correct 2 ms 5076 KB Output is correct
25 Correct 3 ms 5136 KB Output is correct
26 Correct 3 ms 5204 KB Output is correct
27 Correct 3 ms 5204 KB Output is correct
28 Correct 3 ms 5204 KB Output is correct
29 Correct 5 ms 5268 KB Output is correct
30 Correct 5 ms 5240 KB Output is correct
31 Correct 3 ms 5204 KB Output is correct
32 Correct 3 ms 5204 KB Output is correct
33 Correct 3 ms 5204 KB Output is correct
34 Correct 4 ms 5204 KB Output is correct
35 Correct 4 ms 5204 KB Output is correct
36 Correct 4 ms 5264 KB Output is correct
37 Correct 3 ms 5268 KB Output is correct
38 Correct 4 ms 5332 KB Output is correct
39 Correct 4 ms 5332 KB Output is correct
40 Correct 6 ms 5332 KB Output is correct
41 Correct 116 ms 30636 KB Output is correct
42 Correct 130 ms 18660 KB Output is correct
43 Correct 108 ms 18728 KB Output is correct
44 Correct 110 ms 18696 KB Output is correct
45 Correct 141 ms 18824 KB Output is correct
46 Correct 327 ms 31632 KB Output is correct
47 Correct 310 ms 31800 KB Output is correct
48 Correct 299 ms 31716 KB Output is correct
49 Correct 301 ms 31640 KB Output is correct
50 Correct 77 ms 18896 KB Output is correct
51 Correct 78 ms 18908 KB Output is correct
52 Correct 75 ms 18928 KB Output is correct
53 Correct 212 ms 32536 KB Output is correct
54 Correct 203 ms 32468 KB Output is correct
55 Correct 201 ms 32480 KB Output is correct
56 Correct 8 ms 5460 KB Output is correct
57 Correct 590 ms 9644 KB Output is correct
58 Execution timed out 1068 ms 24592 KB Time limit exceeded
59 Halted 0 ms 0 KB -