oj.uz

Submission #667747

# Submission time Handle Problem Language Result Execution time Memory
667747 2022-12-02T00:26:27 Z dutinmeow Cat in a tree (BOI17_catinatree) C++17
100 / 100
 350 ms 35152 KB 
#include <bits/stdc++.h>

namespace std {

template<class Fun>
class y_combinator_result {
	Fun fun_;
public:
	template<class T>
	explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {}

	template<class ...Args>
	decltype(auto) operator()(Args &&...args) {
		return fun_(std::ref(*this), std::forward<Args>(args)...);
	}
};

template<class Fun>
decltype(auto) y_combinator(Fun &&fun) {
	return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun));
}

} // namespace std

struct heavy_light_decomposition {
	std::vector<int> par, dep, hed, tin;

	heavy_light_decomposition(int R, std::vector<std::vector<int>> T) {
		int n = (int)T.size(), time = 0;
		par.resize(n), dep.resize(n);
		hed.resize(n), tin.resize(n);
		par[R] = -1, dep[R] = 0, hed[R] = R;

		std::y_combinator([&](auto self, int u) -> int {
			int sub = 1, mxs = 0;
			for (int &v : T[u]) {
				if (v == par[u])
					continue;
				par[v] = u;
				dep[v] = dep[u] + 1;
				int t = self(v);
				sub += t;
				if (mxs < t) {
					mxs = t;
					std::swap(T[u].front(), v);
				}
			}
			return sub;
		})(R);

		std::y_combinator([&](auto self, int u) -> void {
			tin[u] = time++;
			for (int v : T[u]) {
				if (v == par[u])
					continue;
				hed[v] = v == T[u].front() ? hed[u] : v;
				self(v);
			}
		})(R);
	}

	int lowest_common_ancestor(int u, int v) {
		for (; hed[u] != hed[v]; u = par[hed[u]])
			if (dep[hed[u]] < dep[hed[v]])
				std::swap(u, v);
		return dep[u] < dep[v] ? u : v;
	}

	int distance(int u, int v) { return dep[u] + dep[v] - 2 * dep[lowest_common_ancestor(u, v)]; }
};

class centroid_decomposition {
	int n;
	std::vector<std::vector<int>> tree;
	std::vector<int> parent, weight;
	std::vector<bool> block;

	int initialize_weight(int u, int p) {
		weight[u] = 1;
		for (int v : tree[u]) {
			if (p == v || block[v])
				continue;
			weight[u] += initialize_weight(v, u);
		}
		return weight[u];
	}

	int find_centroid(int w, int u, int p) {
		for (int v : tree[u]) {
			if (p == v || block[v])
				continue;
			if (2 * weight[v] > w)
				return find_centroid(w, v, u);
		}
		return u;
	}

	void initialize_centroids(int c, int p) {
		int w = initialize_weight(c, -1);
		c = find_centroid(w, c, -1);
		parent[c] = p;
		block[c] = true;
		for (int v : tree[c]) {
			if (block[v])
				continue;
			initialize_centroids(v, c);
		}
	}

public:
	centroid_decomposition(const std::vector<std::vector<int>> &_tree) : n((int)_tree.size()), tree(_tree) {
		parent.resize(n);
		weight.resize(n);
		block.assign(n, false);
		initialize_centroids(0, -1);
	}

	int operator[](int i) { return parent[i]; }
};

int main() {
	using namespace std;

	int N, D;
	cin >> N >> D;
	vector<vector<int>> T(N);
	for (int i = 1; i < N; i++) {
		int p;
		cin >> p;
		T[i].push_back(p);
		T[p].push_back(i);
	}

	heavy_light_decomposition hld(0, T);
	centroid_decomposition cd(T);

	vector<int> ord(N);
	iota(ord.begin(), ord.end(), 0);
	sort(ord.begin(), ord.end(), [&hld](int a, int b) {
		return hld.dep[a] > hld.dep[b];
	});

	vector<int> ans;
	vector<int> dis(N, (int)1e9);
	for (int s : ord) {
		int cur = (int)1e9;
		for (int t = s; t != -1; t = cd[t])
			cur = min(cur, dis[t] + hld.distance(s, t));
		if (cur >= D) {
			ans.push_back(s);
			for (int t = s; t != -1; t = cd[t]) {
				dis[t] = min(dis[t], hld.distance(s, t));
			}
		}
	}

	cout << ans.size() << '\n';
	// for (int u : ans)
	// 	cout << u + 1 << ' ';
	// cout << '\n';
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 300 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 1 ms 300 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 296 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 300 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 1 ms 300 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 296 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct
21 Correct 2 ms 596 KB Output is correct
22 Correct 1 ms 332 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 428 KB Output is correct
27 Correct 1 ms 428 KB Output is correct
28 Correct 2 ms 468 KB Output is correct
29 Correct 2 ms 468 KB Output is correct
30 Correct 2 ms 468 KB Output is correct
31 Correct 2 ms 468 KB Output is correct
32 Correct 1 ms 468 KB Output is correct
33 Correct 1 ms 468 KB Output is correct
34 Correct 1 ms 468 KB Output is correct
35 Correct 1 ms 468 KB Output is correct
36 Correct 2 ms 468 KB Output is correct
37 Correct 1 ms 468 KB Output is correct
38 Correct 2 ms 432 KB Output is correct
39 Correct 2 ms 596 KB Output is correct
40 Correct 1 ms 596 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 300 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 1 ms 300 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 296 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct
21 Correct 2 ms 596 KB Output is correct
22 Correct 1 ms 332 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 428 KB Output is correct
27 Correct 1 ms 428 KB Output is correct
28 Correct 2 ms 468 KB Output is correct
29 Correct 2 ms 468 KB Output is correct
30 Correct 2 ms 468 KB Output is correct
31 Correct 2 ms 468 KB Output is correct
32 Correct 1 ms 468 KB Output is correct
33 Correct 1 ms 468 KB Output is correct
34 Correct 1 ms 468 KB Output is correct
35 Correct 1 ms 468 KB Output is correct
36 Correct 2 ms 468 KB Output is correct
37 Correct 1 ms 468 KB Output is correct
38 Correct 2 ms 432 KB Output is correct
39 Correct 2 ms 596 KB Output is correct
40 Correct 1 ms 596 KB Output is correct
41 Correct 134 ms 28920 KB Output is correct
42 Correct 132 ms 15948 KB Output is correct
43 Correct 117 ms 15000 KB Output is correct
44 Correct 123 ms 15120 KB Output is correct
45 Correct 118 ms 15044 KB Output is correct
46 Correct 339 ms 30892 KB Output is correct
47 Correct 327 ms 29952 KB Output is correct
48 Correct 317 ms 29904 KB Output is correct
49 Correct 350 ms 30020 KB Output is correct
50 Correct 71 ms 15692 KB Output is correct
51 Correct 75 ms 15652 KB Output is correct
52 Correct 71 ms 15668 KB Output is correct
53 Correct 183 ms 31016 KB Output is correct
54 Correct 186 ms 31020 KB Output is correct
55 Correct 195 ms 31068 KB Output is correct
56 Correct 2 ms 596 KB Output is correct
57 Correct 18 ms 4388 KB Output is correct
58 Correct 97 ms 19768 KB Output is correct
59 Correct 246 ms 35152 KB Output is correct
60 Correct 131 ms 29568 KB Output is correct
61 Correct 199 ms 28252 KB Output is correct