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Submission #828341

# Submission time Handle Problem Language Result Execution time Memory
828341 2023-08-17T08:40:43 Z serifefedartar Cat in a tree (BOI17_catinatree) C++17
51 / 100
 1000 ms 34080 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 20
#define MAXN 200005

vector<vector<int>> graph;
int up[LOGN][MAXN], depth[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)];
}

vector<int> marked, par, sz;
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] && 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] && u != parent)
			decompose(u, centro);
	}
}

vector<int> nearest;
int main() {
	fast
	int N, D;
	cin >> N >> D;

	graph = vector<vector<int>>(N, vector<int>());
	nearest = vector<int>(N, 1e9);
	marked = vector<int>(N, false);
	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 0 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 340 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 1 ms 432 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 0 ms 340 KB Output is correct
13 Correct 0 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 0 ms 340 KB Output is correct
16 Correct 0 ms 340 KB Output is correct
17 Correct 0 ms 340 KB Output is correct
18 Correct 0 ms 340 KB Output is correct
19 Correct 0 ms 340 KB Output is correct
20 Correct 0 ms 340 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 340 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 1 ms 432 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 0 ms 340 KB Output is correct
13 Correct 0 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 0 ms 340 KB Output is correct
16 Correct 0 ms 340 KB Output is correct
17 Correct 0 ms 340 KB Output is correct
18 Correct 0 ms 340 KB Output is correct
19 Correct 0 ms 340 KB Output is correct
20 Correct 0 ms 340 KB Output is correct
21 Correct 3 ms 724 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 1 ms 468 KB Output is correct
24 Correct 1 ms 468 KB Output is correct
25 Correct 1 ms 596 KB Output is correct
26 Correct 2 ms 596 KB Output is correct
27 Correct 1 ms 596 KB Output is correct
28 Correct 1 ms 596 KB Output is correct
29 Correct 1 ms 596 KB Output is correct
30 Correct 1 ms 596 KB Output is correct
31 Correct 1 ms 596 KB Output is correct
32 Correct 1 ms 596 KB Output is correct
33 Correct 1 ms 596 KB Output is correct
34 Correct 1 ms 596 KB Output is correct
35 Correct 1 ms 596 KB Output is correct
36 Correct 1 ms 596 KB Output is correct
37 Correct 1 ms 596 KB Output is correct
38 Correct 2 ms 596 KB Output is correct
39 Correct 2 ms 724 KB Output is correct
40 Correct 4 ms 724 KB Output is correct

Subtask #3
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 340 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 1 ms 432 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 0 ms 340 KB Output is correct
13 Correct 0 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 0 ms 340 KB Output is correct
16 Correct 0 ms 340 KB Output is correct
17 Correct 0 ms 340 KB Output is correct
18 Correct 0 ms 340 KB Output is correct
19 Correct 0 ms 340 KB Output is correct
20 Correct 0 ms 340 KB Output is correct
21 Correct 3 ms 724 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 1 ms 468 KB Output is correct
24 Correct 1 ms 468 KB Output is correct
25 Correct 1 ms 596 KB Output is correct
26 Correct 2 ms 596 KB Output is correct
27 Correct 1 ms 596 KB Output is correct
28 Correct 1 ms 596 KB Output is correct
29 Correct 1 ms 596 KB Output is correct
30 Correct 1 ms 596 KB Output is correct
31 Correct 1 ms 596 KB Output is correct
32 Correct 1 ms 596 KB Output is correct
33 Correct 1 ms 596 KB Output is correct
34 Correct 1 ms 596 KB Output is correct
35 Correct 1 ms 596 KB Output is correct
36 Correct 1 ms 596 KB Output is correct
37 Correct 1 ms 596 KB Output is correct
38 Correct 2 ms 596 KB Output is correct
39 Correct 2 ms 724 KB Output is correct
40 Correct 4 ms 724 KB Output is correct
41 Correct 92 ms 31800 KB Output is correct
42 Correct 175 ms 16948 KB Output is correct
43 Correct 97 ms 16944 KB Output is correct
44 Correct 117 ms 16940 KB Output is correct
45 Correct 123 ms 16952 KB Output is correct
46 Correct 289 ms 33244 KB Output is correct
47 Correct 284 ms 33176 KB Output is correct
48 Correct 272 ms 33248 KB Output is correct
49 Correct 293 ms 33244 KB Output is correct
50 Correct 78 ms 17388 KB Output is correct
51 Correct 65 ms 17376 KB Output is correct
52 Correct 66 ms 17384 KB Output is correct
53 Correct 183 ms 34080 KB Output is correct
54 Correct 180 ms 34076 KB Output is correct
55 Correct 217 ms 34072 KB Output is correct
56 Correct 7 ms 852 KB Output is correct
57 Correct 636 ms 5616 KB Output is correct
58 Execution timed out 1078 ms 22628 KB Time limit exceeded
59 Halted 0 ms 0 KB -