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Submission #828358

# Submission time Handle Problem Language Result Execution time Memory
828358 2023-08-17T08:51:23 Z serifefedartar Cat in a tree (BOI17_catinatree) C++17
51 / 100
 1000 ms 32872 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 19
#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)];
}
	
bool marked[MAXN];
vector<int> 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() {
	int N, D, x;
	scanf("%d %d", &N, &D);

	graph = vector<vector<int>>(N, vector<int>());
	nearest = vector<int>(N, 1e9);
	par = vector<int>(N, -1);
	sz = vector<int>(N, 1);
	for (int i = 1; i < N; i++) {
		scanf("%d", &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];
			}
		}
	}
	printf("%d\n", ans);
}

Compilation message

catinatree.cpp: In function 'int main()':
catinatree.cpp:87:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |  scanf("%d %d", &N, &D);
      |  ~~~~~^~~~~~~~~~~~~~~~~
catinatree.cpp:94:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |   scanf("%d", &x);
      |   ~~~~~^~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 308 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 1 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 340 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 304 KB Output is correct
14 Correct 0 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 304 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 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 1 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 308 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 1 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 340 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 304 KB Output is correct
14 Correct 0 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 304 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 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 432 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 468 KB Output is correct
26 Correct 1 ms 468 KB Output is correct
27 Correct 1 ms 468 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 568 KB Output is correct
31 Correct 2 ms 596 KB Output is correct
32 Correct 1 ms 596 KB Output is correct
33 Correct 1 ms 564 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 2 ms 568 KB Output is correct
38 Correct 2 ms 596 KB Output is correct
39 Correct 2 ms 596 KB Output is correct
40 Correct 4 ms 696 KB Output is correct

Subtask #3
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 308 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 1 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 340 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 304 KB Output is correct
14 Correct 0 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 304 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 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 432 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 468 KB Output is correct
26 Correct 1 ms 468 KB Output is correct
27 Correct 1 ms 468 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 568 KB Output is correct
31 Correct 2 ms 596 KB Output is correct
32 Correct 1 ms 596 KB Output is correct
33 Correct 1 ms 564 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 2 ms 568 KB Output is correct
38 Correct 2 ms 596 KB Output is correct
39 Correct 2 ms 596 KB Output is correct
40 Correct 4 ms 696 KB Output is correct
41 Correct 110 ms 30848 KB Output is correct
42 Correct 163 ms 16392 KB Output is correct
43 Correct 105 ms 16388 KB Output is correct
44 Correct 129 ms 16476 KB Output is correct
45 Correct 94 ms 16484 KB Output is correct
46 Correct 275 ms 32060 KB Output is correct
47 Correct 274 ms 32060 KB Output is correct
48 Correct 291 ms 32076 KB Output is correct
49 Correct 252 ms 32032 KB Output is correct
50 Correct 91 ms 16820 KB Output is correct
51 Correct 77 ms 16920 KB Output is correct
52 Correct 74 ms 16816 KB Output is correct
53 Correct 179 ms 32868 KB Output is correct
54 Correct 180 ms 32872 KB Output is correct
55 Correct 200 ms 32868 KB Output is correct
56 Correct 6 ms 828 KB Output is correct
57 Correct 588 ms 5556 KB Output is correct
58 Execution timed out 1047 ms 22240 KB Time limit exceeded
59 Halted 0 ms 0 KB -