Submission #531851

#	Time	Username	Problem	Language	Result	Execution time	Memory
531851		Stickfish	Cat in a tree (BOI17_catinatree)	C++17	51 / 100	21 ms	9616 KiB

catinatree

#include <iostream>
#include <vector>
using namespace std;

const int MAXN = 1580;
vector<int> edg[MAXN];
int depth[MAXN];
int dp[MAXN][MAXN];

signed main() {
    int n, d;
    cin >> n >> d;
    for (int i = 1; i < n; ++i) {
        int rt;
        cin >> rt;
        edg[rt].push_back(i);
        depth[i] = depth[rt] + 1;
    }
    for (int i = n - 1; i >= 0; --i) {
        dp[i][depth[i]] = 1;
        if (d + depth[i] < n) {
            for (auto u : edg[i]) {
                dp[i][depth[i]] += dp[u][d + depth[i]];
            }
        }
        for (int t = depth[i] + 1; t < n; ++t) {
            int d0 = min(n, max(t, depth[i] * 2 + d - t));
            int mx = 0;
            for (auto u : edg[i]) {
                dp[i][t] += dp[u][d0];
                mx = max(mx, dp[u][t] - dp[u][d0]);
            }
            dp[i][t] += mx;
        }
        for (int t = n - 2; t >= 0; --t) {
            dp[i][t] = max(dp[i][t], dp[i][t + 1]);
        }
        //cout << i << ": ";
        //for (int j = 0; j < n; ++j)
            //cout << dp[i][j] << ' ';
        //cout << '\n';
    }
    cout << dp[0][0] << '\n';
}

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