Submission #930942

#	Time	Username	Problem	Language	Result	Execution time	Memory
930942		NintsiChkhaidze	Cat in a tree (BOI17_catinatree)	C++17	51 / 100	9 ms	31584 KiB

catinatree

#include <bits/stdc++.h>
#define ll long long
#define s second
#define f first
#define pb push_back
#define pii pair <int,int>
#define left (h<<1),l,(l + r)/2
#define right ((h<<1)|1),(l + r)/2 + 1,r
using namespace std;
 
const int N = 5e3 + 5;
vector <int> v[N];
int dp[N][N],dpnew[N],K;

int dfs(int x,int par){
	dp[x][0] = 1;
	int s = 1;

	int mx = 0;
	for (int to: v[x]){
		int y1 = dfs(to,x);
		s = max(s,y1 + 1);

		for (int i = 0; i <= mx; i++){
			for (int j = 0; j <= y1; j++){
				int dist = i + j + 1;
				if (dist < K) continue;
				dpnew[min(i,j + 1)] = max(dpnew[min(i,j + 1)],dp[x][i] + dp[to][j]);
			}
		}

		for (int j = 0; j <= y1; j++)
			dpnew[j + 1] = max(dpnew[j + 1],dp[to][j]);
		
		mx=max(mx,y1);
		for (int j = 0; j <= mx; j++)
			dp[x][j] = max(dp[x][j],dpnew[j]),dpnew[j] = 0;
	}

	return s;
}

signed main(){
	ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
	
	int n;
	cin>>n>>K;

	for (int i = 2; i <= n; i++){
		int par;
		cin>>par;
		v[par + 1].pb(i);
	}
	dfs(1,1);

	int ans=0;
	for (int i = 0; i <= n; i++){
		ans=max(ans,dp[1][i]);
	}
	cout<<ans<<endl;
}	

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