Submission #469355

#	Time	Username	Problem	Language	Result	Execution time	Memory
469355		arujbansal	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	161 ms	93892 KiB

catinatree

#include <bits/stdc++.h>

using namespace std;

void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail>
void dbg_out(Head H, Tail... T) { cerr << ' ' << H; dbg_out(T...); }
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)

#define rng_init mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
#define rng_seed(x) mt19937 rng(x)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int) (x).size()
// #define int long long

const int MXN = 2e5 + 5, INF = 1e9 + 5;
int N, D;
vector<int> g[MXN];

deque<int> dfs(int u, int p) {
    deque<int> res = {1};

    for (const auto &v : g[u]) {
        if (v == p) continue;

        deque<int> merge = dfs(v, u);
        merge.push_front(merge.front());

        if (sz(merge) > sz(res))
            swap(merge, res);

        for (int i = 0; i < sz(merge); i++) {
            int val1 = merge[i] + (D - i < sz(res) ? res[max(i, D - i)] : 0);
            int val2 = res[i] + (D - i < sz(merge) ? merge[max(i, D - i)] : 0);
            res[i] = max({res[i], val1, val2});
        }

        for (int i = sz(merge) - 2; i >= 0; i--)
            res[i] = max(res[i], res[i + 1]);
    }

    return res;
}

void solve() {
    cin >> N >> D;

    for (int i = 1; i < N; i++) {
        int x;
        cin >> x;

        g[x].push_back(i);
        g[i].push_back(x);
    }   

    cout << dfs(0, -1).front();
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int TC = 1;
    // cin >> TC;
    while (TC--) solve();
}

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