Submission #346386

#	Time	Username	Problem	Language	Result	Execution time	Memory
346386		alishahali1382	Cat in a tree (BOI17_catinatree)	C++14	100 / 100	29 ms	5484 KiB

catinatree

#include <bits/stdc++.h>
#pragma GCC optimize ("O2,unroll-loops")
//#pragma GCC optimize("no-stack-protector,fast-math")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) {cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;}
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout<<x<<'\n', 0;

const int inf=1000000010;
const ll INF=10000000000000010LL;
const int mod=1000000007;
const int MAXN=200010, LOG=20;

int n, D, u, v, x, y, t, a, b, ans;
int par[MAXN];
pii dp[MAXN][2], dpt[2];

inline void Add(int v, int u){
	for (int i:{0, 1}) dpt[i]=dp[v][i];
	for (int i:{0, 1}) for (int j:{0, 1}) if (dpt[i].second+dp[u][j].second>=D){
		pii p={dpt[i].first+dp[u][j].first, min(dpt[i].second, dp[u][j].second)};
		if (p>dp[v][0]) swap(dp[v][0], p);
		if (p.first!=dp[v][0].first && p>dp[v][1]) swap(dp[v][1], p);
	}
}

int main(){
	ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	//freopen("input.txt", "r", stdin);
	//freopen("output.txt", "w", stdout);
	cin>>n>>D;
	for (int i=1; i<n; i++) cin>>par[i];
	for (int i=0; i<n; i++) dp[i][0]={1, 0}, dp[i][1]={0, inf};
	for (int i=n-1; i; i--){
		dp[i][0].second++;
		dp[i][1].second++;
		Add(par[i], i);
	}
	cout<<dp[0][0].first<<"\n";
	
	return 0;
}
/*
6 4
0 1 2 3 2

*/

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