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답안 #828403

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
828403 2023-08-17T09:18:57 Z serifefedartar Cat in a tree (BOI17_catinatree) C++17
100 / 100
 363 ms 39928 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> nearest;
int up[LOGN][MAXN], depth[MAXN], par[MAXN], sz[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) {
	sz[node] = 1;
	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() {
	fast
	memset(par, -1, sizeof(par));
	int N, D;
	cin >> N >> D;

	nearest = vector<int>(N, 1e9);
	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

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 5844 KB Output is correct
2 Correct 2 ms 5844 KB Output is correct
3 Correct 2 ms 5844 KB Output is correct
4 Correct 2 ms 5844 KB Output is correct
5 Correct 2 ms 5844 KB Output is correct
6 Correct 2 ms 5844 KB Output is correct
7 Correct 2 ms 5844 KB Output is correct
8 Correct 3 ms 5844 KB Output is correct
9 Correct 3 ms 5844 KB Output is correct
10 Correct 3 ms 5844 KB Output is correct
11 Correct 2 ms 5844 KB Output is correct
12 Correct 2 ms 5844 KB Output is correct
13 Correct 3 ms 5844 KB Output is correct
14 Correct 3 ms 5844 KB Output is correct
15 Correct 2 ms 5844 KB Output is correct
16 Correct 3 ms 5952 KB Output is correct
17 Correct 2 ms 5844 KB Output is correct
18 Correct 2 ms 5844 KB Output is correct
19 Correct 2 ms 5844 KB Output is correct
20 Correct 2 ms 5844 KB Output is correct

Subtask #2
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 5844 KB Output is correct
2 Correct 2 ms 5844 KB Output is correct
3 Correct 2 ms 5844 KB Output is correct
4 Correct 2 ms 5844 KB Output is correct
5 Correct 2 ms 5844 KB Output is correct
6 Correct 2 ms 5844 KB Output is correct
7 Correct 2 ms 5844 KB Output is correct
8 Correct 3 ms 5844 KB Output is correct
9 Correct 3 ms 5844 KB Output is correct
10 Correct 3 ms 5844 KB Output is correct
11 Correct 2 ms 5844 KB Output is correct
12 Correct 2 ms 5844 KB Output is correct
13 Correct 3 ms 5844 KB Output is correct
14 Correct 3 ms 5844 KB Output is correct
15 Correct 2 ms 5844 KB Output is correct
16 Correct 3 ms 5952 KB Output is correct
17 Correct 2 ms 5844 KB Output is correct
18 Correct 2 ms 5844 KB Output is correct
19 Correct 2 ms 5844 KB Output is correct
20 Correct 2 ms 5844 KB Output is correct
21 Correct 3 ms 6228 KB Output is correct
22 Correct 3 ms 5972 KB Output is correct
23 Correct 3 ms 5972 KB Output is correct
24 Correct 3 ms 5972 KB Output is correct
25 Correct 3 ms 5972 KB Output is correct
26 Correct 3 ms 5972 KB Output is correct
27 Correct 3 ms 5972 KB Output is correct
28 Correct 3 ms 6100 KB Output is correct
29 Correct 3 ms 6100 KB Output is correct
30 Correct 3 ms 6100 KB Output is correct
31 Correct 3 ms 6100 KB Output is correct
32 Correct 3 ms 6028 KB Output is correct
33 Correct 3 ms 6100 KB Output is correct
34 Correct 3 ms 6100 KB Output is correct
35 Correct 3 ms 6100 KB Output is correct
36 Correct 4 ms 6100 KB Output is correct
37 Correct 3 ms 6100 KB Output is correct
38 Correct 3 ms 6100 KB Output is correct
39 Correct 3 ms 6100 KB Output is correct
40 Correct 4 ms 6228 KB Output is correct

Subtask #3
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 5844 KB Output is correct
2 Correct 2 ms 5844 KB Output is correct
3 Correct 2 ms 5844 KB Output is correct
4 Correct 2 ms 5844 KB Output is correct
5 Correct 2 ms 5844 KB Output is correct
6 Correct 2 ms 5844 KB Output is correct
7 Correct 2 ms 5844 KB Output is correct
8 Correct 3 ms 5844 KB Output is correct
9 Correct 3 ms 5844 KB Output is correct
10 Correct 3 ms 5844 KB Output is correct
11 Correct 2 ms 5844 KB Output is correct
12 Correct 2 ms 5844 KB Output is correct
13 Correct 3 ms 5844 KB Output is correct
14 Correct 3 ms 5844 KB Output is correct
15 Correct 2 ms 5844 KB Output is correct
16 Correct 3 ms 5952 KB Output is correct
17 Correct 2 ms 5844 KB Output is correct
18 Correct 2 ms 5844 KB Output is correct
19 Correct 2 ms 5844 KB Output is correct
20 Correct 2 ms 5844 KB Output is correct
21 Correct 3 ms 6228 KB Output is correct
22 Correct 3 ms 5972 KB Output is correct
23 Correct 3 ms 5972 KB Output is correct
24 Correct 3 ms 5972 KB Output is correct
25 Correct 3 ms 5972 KB Output is correct
26 Correct 3 ms 5972 KB Output is correct
27 Correct 3 ms 5972 KB Output is correct
28 Correct 3 ms 6100 KB Output is correct
29 Correct 3 ms 6100 KB Output is correct
30 Correct 3 ms 6100 KB Output is correct
31 Correct 3 ms 6100 KB Output is correct
32 Correct 3 ms 6028 KB Output is correct
33 Correct 3 ms 6100 KB Output is correct
34 Correct 3 ms 6100 KB Output is correct
35 Correct 3 ms 6100 KB Output is correct
36 Correct 4 ms 6100 KB Output is correct
37 Correct 3 ms 6100 KB Output is correct
38 Correct 3 ms 6100 KB Output is correct
39 Correct 3 ms 6100 KB Output is correct
40 Correct 4 ms 6228 KB Output is correct
41 Correct 86 ms 30028 KB Output is correct
42 Correct 145 ms 18500 KB Output is correct
43 Correct 98 ms 18600 KB Output is correct
44 Correct 149 ms 18488 KB Output is correct
45 Correct 147 ms 18484 KB Output is correct
46 Correct 336 ms 31004 KB Output is correct
47 Correct 320 ms 31084 KB Output is correct
48 Correct 302 ms 31080 KB Output is correct
49 Correct 290 ms 31088 KB Output is correct
50 Correct 70 ms 18940 KB Output is correct
51 Correct 69 ms 18932 KB Output is correct
52 Correct 74 ms 18932 KB Output is correct
53 Correct 242 ms 31848 KB Output is correct
54 Correct 203 ms 31848 KB Output is correct
55 Correct 232 ms 31844 KB Output is correct
56 Correct 5 ms 6216 KB Output is correct
57 Correct 26 ms 10280 KB Output is correct
58 Correct 147 ms 25512 KB Output is correct
59 Correct 363 ms 39928 KB Output is correct
60 Correct 99 ms 31700 KB Output is correct
61 Correct 156 ms 30872 KB Output is correct