Submission #244535

#	Time	Username	Problem	Language	Result	Execution time	Memory
244535		kshitij_sodani	Cat in a tree (BOI17_catinatree)	C++17	0 / 100	10 ms	9728 KiB

catinatree

#include <bits/stdc++.h>
using namespace std;
typedef int64_t llo;
#define mp make_pair
#define pb push_back
#define a first 
#define b second
//#define endl '\n'
 
int n,d;
int ans=0;
set<int> adj[200001];
int vis[200001];
vector<pair<int,int>> cur;
void dfs(int no,int par=-1,int levv=0){
	cur.pb({levv,no});
	for(auto j:adj[no]){
		if(j==par){
			continue;
		}
		dfs(j,no,levv+1);
	}
}
vector<int> kk;
void dfs2(int no,int par=-1,int levv=0){
	vis[no]=1;
	kk.pb(no);
	if(levv<d-1){
		for(auto j:adj[no]){
			if(j==par){
				continue;
			}
			dfs2(j,no,levv+1);
		}
	}
}
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cin>>n>>d;
	for(int i=1;i<n;i++){
		int aa;
		cin>>aa;
		adj[aa].insert(i);
		adj[i].insert(aa);
	}
	dfs(0);
	sort(cur.begin(),cur.end());
	reverse(cur.begin(),cur.end());

	for(auto no:cur){
		if(vis[no.b]){
			continue;
		}
		ans+=1;
		dfs2(no.b);
		for(auto j:kk){
			for(auto ll:adj[j]){
				if(adj[ll].find(j)!=adj[ll].end()){
					adj[ll].erase(j);
				}
			}
			adj[j].clear();
		}
		kk.clear();
	}
	cout<<ans<<endl;




	return 0;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 40
• Subtask 3: 0 / 49