Submission #360188

#	Time	Username	Problem	Language	Result	Execution time	Memory
360188		iamsleepy	Cat in a tree (BOI17_catinatree)	C++14	51 / 100	1081 ms	20840 KiB

catinatree

#include<bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
using namespace std;
const int mxn=2e5+5;
const int inf=1e9;
int d;
int level[mxn];
set<pii> st;
vector<int> adj[mxn];

void dfs(int cur,int prev,int dist,int x) {
	if(dist >= d) return;
	if(st.find({level[cur],cur}) != st.end()) st.erase({level[cur],cur});
	for(int u : adj[cur]) {
		if(u == prev || (cur == x && level[u] > level[cur]) ) continue;
		dfs(u,cur,dist + 1,x);
	}
}


void DFS(int cur,int prev) {
	level[cur] = level[prev] + 1;
	for(int u : adj[cur]) {
		if(u != prev) DFS(u,cur);
	}
}


int main() {
	int n;
	cin>>n;

	cin>>d;
	for(int i = 1; i < n; i++) {
		int u;
		cin>>u;
		adj[u].push_back(i);
		adj[i].push_back(u);
	}

	level[0] = 0;
	DFS(0,0);
	for(int i = 0; i < n; i++) st.insert({level[i],i});
	int res = 0;
	while(!st.empty()) {
		auto it = st.rbegin();
		int u = it->second;
		res++;
		dfs(u,-1,0,u);
	}
	cout<<res<<endl;




}

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