Submission #1242488

#	Time	Username	Problem	Language	Result	Execution time	Memory
1242488		bangan	Beech Tree (IOI23_beechtree)	C++20	0 / 100	3 ms	4936 KiB

beechtree

#include "beechtree.h"
#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define ALL(a) a.begin(), a.end()

const int MXN = 200200;

int n;
int m;
vector<int> p;
vector<int> c;
vector<int> adj[MXN];

bool is_subset(vector<int> a, vector<int> b) {
    set<int> all;
    for (int x : b) all.insert(c[x]);
    for (int x : a) if (!all.contains(c[x])) return false;
    return true;
}

vector<int> beechtree(int N, int M, vector<int> P, vector<int> C) {
    n = N;
    m = M;
    p = P;
    c = C;
    for (int i=1; i<n; i++) adj[p[i]].pb(i);

    vector<int> ans(n);
    auto dfs = [&](auto self, int v) -> vector<int> {
        vector<int> sub;
        for (int u : adj[v]) {
            auto vec = self(self, u);
            for (auto it : vec) sub.pb(it);
        }

        sort(ALL(sub), [&](int x, int y) {
            return c[x] < c[y];
        });
        
        ans[v] = 1;
        for (int i=0; i+1 < sub.size(); i++) if (c[sub[i]] == c[sub[i+1]]) ans[v] = 0;
        
        sub.pb(v);
        return sub;
    };

    vector<vector<int>> vec;
    for (int v : adj[0]) vec.pb(dfs(dfs, v));

    sort(ALL(vec), [&](auto x, auto y) {
        return x.size() < y.size();
    });

    ans[0] = 1;
    for (int v : adj[0]) if (ans[v]==0) ans[0] = 0;
    for (int i=1; i<vec.size(); i++) if (!is_subset(vec[i-1], vec[i])) ans[0] = 0;
    return ans;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 9
• Subtask 2: 0 / 5
• Subtask 3: 0 / 9
• Subtask 4: 0 / 8
• Subtask 5: 0 / 14
• Subtask 6: 0 / 14
• Subtask 7: 0 / 12
• Subtask 8: 0 / 17
• Subtask 9: 0 / 12