Submission #847684

#	Time	Username	Problem	Language	Result	Execution time	Memory
847684		vjudge1	Beech Tree (IOI23_beechtree)	C++17	0 / 100	96 ms	54992 KiB

beechtree

#include "beechtree.h"

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

std::vector<int> beechtree(int N, int M, std::vector<int> P, std::vector<int> C) {
        vector<vector<int>> adj(N);
        for (int i = 1; i < N; i++) {
                adj[P[i]].emplace_back(i);
        }
        vector<vector<int>> c(N);
        for (int i = 1; i < N; i++) {
                c[P[i]].emplace_back(C[i] - 1);
        }
        vector<int> f(N, 0);
        vector<int> d(N);
        function<void(int)> dfs = [&](int u) {
                int cnt = 0;
                for (int v : adj[u]) {
                        dfs(v);
                        d[u] = max(d[v] + 1, d[u]);
                        cnt += adj[v].size() != 0;
                }
                if (d[u] > 2) return void(f[u] = 0);
                if (d[u] < 2) return void(f[u] = 1);
                if (cnt == 1) {
                        f[u] = 1;
                        vector<int> ord(1, u);
                        for (int v : adj[u]) ord.emplace_back(v);
                        sort(ord.begin(), ord.end(), [&](int i, int j) {
                                return c[i].size() == c[j].size() ? d[i] > d[j] : c[i].size() < c[j].size();
                        });
                        if (ord[0] != u) return void(f[u] = 0);
                        for (int i = 1; i < ord.size(); i++) {
                                for (int j : c[ord[i]]) {
                                        if (!binary_search(c[ord[i - 1]].begin(), c[ord[i - 1]].end(), j)) return void(f[u] = 0);
                                }
                        }
                }
                if (cnt > 1) f[u] = 0;
        };
        dfs(0);
        for (int i = 0; i < N; i++) {
                sort(c[i].begin(), c[i].end());
                for (int j = 1; j < c[i].size(); j++) {
                        if (c[i][j] == c[i][j - 1]) f[i] = 0;
                }
        }
        return f;
}

Compilation message (stderr)

beechtree.cpp: In lambda function:
beechtree.cpp:34:43: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |                         for (int i = 1; i < ord.size(); i++) {
      |                                         ~~^~~~~~~~~~~~
beechtree.cpp: In function 'std::vector<int> beechtree(int, int, std::vector<int>, std::vector<int>)':
beechtree.cpp:45:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |                 for (int j = 1; j < c[i].size(); j++) {
      |                                 ~~^~~~~~~~~~~~~

• 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