Submission #237235

#	Time	Username	Problem	Language	Result	Execution time	Memory
237235		IgorI	Cat in a tree (BOI17_catinatree)	C++17	51 / 100	285 ms	524288 KiB

catinatree

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N = 200000;
const int K = 2000;

int n, d;
int dp[N][K];
int p[N];
vector<int> graph[N];

void dfs(int v)
{
    for (auto u : graph[v]) dfs(u);
    dp[v][0] = 1;
    for (auto u : graph[v]) dp[v][0] += dp[u][d - 1];
    for (int j = 1; j <= d; j++)
    {
        int allow = d - j - 1;
        allow = max(allow, j - 1);
        for (auto u : graph[v])
        {
            int res = dp[u][j - 1];
            for (auto w : graph[v]) if (w != u)
                res += dp[w][allow];
            dp[v][j] = max(dp[v][j], res);
        }
    }
    for (int j = d - 1; j >= 0; j--) dp[v][j] = max(dp[v][j], dp[v][j + 1]);
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> d;
    if (d == 1) cout << n, exit(0);
    for (int i = 1; i < n; i++)
    {
        cin >> p[i];
        graph[p[i]].push_back(i);
    }
    if (d < K)
    {
        dfs(0);
        cout << dp[0][0];
    }
    else
    {
        cout << 1;
    }
}

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