Submission #963670

#	Time	Username	Problem	Language	Result	Execution time	Memory
963670		pcc	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	31 ms	15700 KiB

catinatree

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>

const int mxn = 2e5+10;
int N,D;
vector<int> tree[mxn];
pii dp[mxn];

void dfs(int now){
	dp[now] = pii(1,0);
	for(auto nxt:tree[now]){
		dfs(nxt);
		dp[now].fs += dp[nxt].fs;
		if(dp[now].sc+dp[nxt].sc+1<D){
			dp[now].fs--;
			dp[now].sc = max(dp[now].sc,dp[nxt].sc+1);
		}
		else{
			dp[now].sc = min(dp[now].sc,dp[nxt].sc+1);
		}
	}
	return;
}

int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>N>>D;
	for(int i = 1;i<N;i++){
		int p;
		cin>>p;
		tree[p].push_back(i);
	}
	dfs(0);
	cout<<dp[0].fs;
}

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