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Submission #415294

# Submission time Handle Problem Language Result Execution time Memory
415294 2021-05-31T20:21:57 Z Blagojce Cat in a tree (BOI17_catinatree) C++11
100 / 100
 619 ms 39492 KB 
#include <bits/stdc++.h>
#define fr(i, n, m) for(int i = (n); i < (m); i ++)
#define pb push_back
#define st first
#define nd second
#define pq priority_queue
#define all(x) begin(x), end(x)
  
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pii;
const ll inf = 1e18;
const int i_inf = 1e9;
const ll mod = 1e9+7;

mt19937 _rand(time(NULL));
const int mxn = 2e5;

int n, d;

vector<int> g[mxn];

int sub[mxn];
bool deleted[mxn];

int cn;


int dep[mxn];
int sparse[mxn][19];

void dfs(int u, int p){
	sparse[u][0] = p;
	fr(i, 1, 19) sparse[u][i] = sparse[sparse[u][i-1]][i-1];
	for(auto e : g[u]){
		if(e == p) continue;
		dep[e] = dep[u] + 1;
		dfs(e, u);
	}
}

void dfs0(int u, int p){
	sub[u] = 1;
	for(auto e : g[u]){
		if(e == p || deleted[e]) continue;
		dfs0(e, u);
		sub[u] += sub[e];
	}
}

int dfs1(int u, int p){
	for(auto e : g[u]){
		if(e == p || deleted[e]) continue;
		if(sub[e] > cn /2) return dfs1(e, u);
	}
	return u;
}
int link[mxn];


void decompose(int u, int p){
	
	
	dfs0(u, u);
	cn = sub[u];
	int cen = dfs1(u, u);
	link[cen] = p;
	
	deleted[cen] = true;
	for(auto e : g[cen]){
		if(!deleted[e]){
			decompose(e, cen);
		}
	}
}


int lca(int a, int b){
	int d = min(dep[a], dep[b]);
	for(int i = 18; i >= 0; i --){
		if(dep[a] - (1<<i) >= d){
			a = sparse[a][i];
		}
		if(dep[b] - (1<<i) >= d){
			b = sparse[b][i];
		}
	}
	if(a == b) return a;
	
	for(int i = 18; i >= 0; i--){
		if(sparse[a][i] != sparse[b][i]){
			a = sparse[a][i];
			b = sparse[b][i];
		}
	}
	return sparse[a][0];
}

int minw[mxn];

bool check(int u){
	int x = u;
	while(x != -1){
		int w = minw[x] + dep[x] + dep[u] - 2*dep[lca(x, u)];
		
		if(w < d) return false;
		
		x = link[x];
	}
	
	return true;
}
void update(int u){
	int x = u;
	while(x != -1){
		minw[x] = min(minw[x], dep[x] + dep[u] - 2*dep[lca(x, u)]);
		x = link[x];
	}

}

void solve(){
	cin >> n >> d;
	fr(i, 1, n){
		int x;
		cin >> x;
		g[i].pb(x);
		g[x].pb(i);
	}
	dfs(0, 0);
	decompose(0, -1);
	vector<int> v;
	fr(i, 0, n) v.pb(i);
	sort(all(v), [](const int &i, const int &j){
		return dep[i] > dep[j];
	});
	fr(i, 0, n){
		minw[i] = 1e9;
	}
	int ans = 0;
	for(auto u : v){
		if(check(u)){
			update(u);
			++ans;
		}
	}
	cout<<ans<<endl;
}
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	solve();
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4968 KB Output is correct
2 Correct 5 ms 4940 KB Output is correct
3 Correct 4 ms 4940 KB Output is correct
4 Correct 4 ms 4984 KB Output is correct
5 Correct 4 ms 4940 KB Output is correct
6 Correct 4 ms 4940 KB Output is correct
7 Correct 4 ms 4976 KB Output is correct
8 Correct 4 ms 4940 KB Output is correct
9 Correct 5 ms 5028 KB Output is correct
10 Correct 4 ms 5024 KB Output is correct
11 Correct 4 ms 4940 KB Output is correct
12 Correct 5 ms 4940 KB Output is correct
13 Correct 5 ms 4960 KB Output is correct
14 Correct 4 ms 5024 KB Output is correct
15 Correct 4 ms 4940 KB Output is correct
16 Correct 4 ms 4940 KB Output is correct
17 Correct 3 ms 4940 KB Output is correct
18 Correct 5 ms 5028 KB Output is correct
19 Correct 5 ms 4940 KB Output is correct
20 Correct 6 ms 4940 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4968 KB Output is correct
2 Correct 5 ms 4940 KB Output is correct
3 Correct 4 ms 4940 KB Output is correct
4 Correct 4 ms 4984 KB Output is correct
5 Correct 4 ms 4940 KB Output is correct
6 Correct 4 ms 4940 KB Output is correct
7 Correct 4 ms 4976 KB Output is correct
8 Correct 4 ms 4940 KB Output is correct
9 Correct 5 ms 5028 KB Output is correct
10 Correct 4 ms 5024 KB Output is correct
11 Correct 4 ms 4940 KB Output is correct
12 Correct 5 ms 4940 KB Output is correct
13 Correct 5 ms 4960 KB Output is correct
14 Correct 4 ms 5024 KB Output is correct
15 Correct 4 ms 4940 KB Output is correct
16 Correct 4 ms 4940 KB Output is correct
17 Correct 3 ms 4940 KB Output is correct
18 Correct 5 ms 5028 KB Output is correct
19 Correct 5 ms 4940 KB Output is correct
20 Correct 6 ms 4940 KB Output is correct
21 Correct 6 ms 5324 KB Output is correct
22 Correct 5 ms 5068 KB Output is correct
23 Correct 5 ms 5024 KB Output is correct
24 Correct 5 ms 5128 KB Output is correct
25 Correct 7 ms 5152 KB Output is correct
26 Correct 5 ms 5068 KB Output is correct
27 Correct 6 ms 5152 KB Output is correct
28 Correct 6 ms 5196 KB Output is correct
29 Correct 7 ms 5196 KB Output is correct
30 Correct 5 ms 5196 KB Output is correct
31 Correct 6 ms 5196 KB Output is correct
32 Correct 5 ms 5196 KB Output is correct
33 Correct 6 ms 5196 KB Output is correct
34 Correct 4 ms 5196 KB Output is correct
35 Correct 6 ms 5196 KB Output is correct
36 Correct 5 ms 5152 KB Output is correct
37 Correct 5 ms 5196 KB Output is correct
38 Correct 5 ms 5196 KB Output is correct
39 Correct 5 ms 5196 KB Output is correct
40 Correct 7 ms 5324 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4968 KB Output is correct
2 Correct 5 ms 4940 KB Output is correct
3 Correct 4 ms 4940 KB Output is correct
4 Correct 4 ms 4984 KB Output is correct
5 Correct 4 ms 4940 KB Output is correct
6 Correct 4 ms 4940 KB Output is correct
7 Correct 4 ms 4976 KB Output is correct
8 Correct 4 ms 4940 KB Output is correct
9 Correct 5 ms 5028 KB Output is correct
10 Correct 4 ms 5024 KB Output is correct
11 Correct 4 ms 4940 KB Output is correct
12 Correct 5 ms 4940 KB Output is correct
13 Correct 5 ms 4960 KB Output is correct
14 Correct 4 ms 5024 KB Output is correct
15 Correct 4 ms 4940 KB Output is correct
16 Correct 4 ms 4940 KB Output is correct
17 Correct 3 ms 4940 KB Output is correct
18 Correct 5 ms 5028 KB Output is correct
19 Correct 5 ms 4940 KB Output is correct
20 Correct 6 ms 4940 KB Output is correct
21 Correct 6 ms 5324 KB Output is correct
22 Correct 5 ms 5068 KB Output is correct
23 Correct 5 ms 5024 KB Output is correct
24 Correct 5 ms 5128 KB Output is correct
25 Correct 7 ms 5152 KB Output is correct
26 Correct 5 ms 5068 KB Output is correct
27 Correct 6 ms 5152 KB Output is correct
28 Correct 6 ms 5196 KB Output is correct
29 Correct 7 ms 5196 KB Output is correct
30 Correct 5 ms 5196 KB Output is correct
31 Correct 6 ms 5196 KB Output is correct
32 Correct 5 ms 5196 KB Output is correct
33 Correct 6 ms 5196 KB Output is correct
34 Correct 4 ms 5196 KB Output is correct
35 Correct 6 ms 5196 KB Output is correct
36 Correct 5 ms 5152 KB Output is correct
37 Correct 5 ms 5196 KB Output is correct
38 Correct 5 ms 5196 KB Output is correct
39 Correct 5 ms 5196 KB Output is correct
40 Correct 7 ms 5324 KB Output is correct
41 Correct 145 ms 30332 KB Output is correct
42 Correct 242 ms 18468 KB Output is correct
43 Correct 183 ms 18404 KB Output is correct
44 Correct 233 ms 18364 KB Output is correct
45 Correct 174 ms 18428 KB Output is correct
46 Correct 520 ms 31648 KB Output is correct
47 Correct 494 ms 31752 KB Output is correct
48 Correct 439 ms 31764 KB Output is correct
49 Correct 619 ms 31676 KB Output is correct
50 Correct 120 ms 18684 KB Output is correct
51 Correct 121 ms 18604 KB Output is correct
52 Correct 111 ms 18696 KB Output is correct
53 Correct 274 ms 32204 KB Output is correct
54 Correct 312 ms 32164 KB Output is correct
55 Correct 282 ms 32244 KB Output is correct
56 Correct 8 ms 5452 KB Output is correct
57 Correct 37 ms 9412 KB Output is correct
58 Correct 192 ms 25504 KB Output is correct
59 Correct 514 ms 39492 KB Output is correct
60 Correct 167 ms 31032 KB Output is correct
61 Correct 286 ms 30256 KB Output is correct