Submission #732117

#	Time	Username	Problem	Language	Result	Execution time	Memory
732117		Trunkty	Cat in a tree (BOI17_catinatree)	C++14	100 / 100	83 ms	25192 KiB

catinatree

#include <bits/extc++.h>
using namespace std;
typedef long long ll;
#define int ll

int n,d;
vector<int> roads[200005];
int dp[200005],mini[200005];

void dfs(int x){
    vector<int> v;
    for(int i:roads[x]){
        dfs(i);
        dp[x] += dp[i];
        v.push_back(mini[i]);
    }
    if(v.size()==0){
        dp[x]++;
    }
    else{
        sort(v.begin(),v.end(),greater<int>());
        while(v.size()>=2){
            int a = v.back();
            v.pop_back();
            if(a+v.back()+2LL<d){
                dp[x]--;
                continue;
            }
            else{
                v.push_back(a);
                break;
            }
        }
        if(v.back()+1LL<d){
            mini[x] = v.back()+1LL;
        }
        else{
            dp[x]++;
        }
    }
}

signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
    cin >> n >> d;
    for(int i=1;i<=n-1;i++){
        int a;
        cin >> a;
        roads[a].push_back(i);
    }
    dfs(0);
    cout << dp[0] << "\n";
	return 0;
}

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