Submission #841413

#	Time	Username	Problem	Language	Result	Execution time	Memory
841413		model_code	Beech Tree (IOI23_beechtree)	C++17	14 / 100	2077 ms	858084 KiB

beechtree

// correct/sol_db_twoColors-mediumN.cpp

#include "beechtree.h"
#include <bits/stdc++.h>

#define all(x) (x).begin(), (x).end()
#define xx first
#define yy second

using namespace std;
typedef pair<int, int> pii;
const int N = 2e5 + 1;

struct Graph
{
    int cnt[N];
    bool con[N];
    vector<int> adj[N][2];
    vector<pii> srt[N];
} graph;

bool check(int v, int u)
{
    for (int c = 0; c < 2; ++c)
    {
        if (graph.adj[v][c].empty())
        {
            continue;
        }
        if (graph.adj[u][c].empty())
        {
            return false;
        }
        if (graph.cnt[graph.adj[v][c][0]] > graph.cnt[graph.adj[u][c][0]])
        {
            return false;
        }
    }
    return true;
}

int dfs(int u)
{
    graph.cnt[u] = 1;
    graph.con[u] = true;

    for (int c = 0; c < 2; ++c)
    {
        auto &vec = graph.adj[u][c];
        graph.con[u] &= vec.size() <= 1;

        for (int v : vec)
        {
            int cnv = dfs(v);
            if (cnv == -1)
            {
                graph.con[u] = false;
            }
            else
            {
                graph.cnt[u] += cnv;
            }
            for (pii p : graph.srt[v])
            {
                graph.srt[u].push_back(p);
            }
        }
    }
    graph.srt[u].push_back({graph.cnt[u], u});
    sort(all(graph.srt[u]));

    for (int i = 0; i < graph.srt[u].size() - 1; ++i)
    {
        graph.con[u] = graph.con[u] & check(graph.srt[u][i].yy, graph.srt[u][i + 1].yy);
    }
    return graph.con[u] ? graph.cnt[u] : -1;
}

vector<int> beechtree(int n, int m, vector<int> P, vector<int> C)
{
    for (int i = 1; i < n; ++i)
    {
        int p = P[i];
        int c = C[i];
        graph.adj[p][c - 1].push_back(i);
    }
    dfs(0);

    vector<int> ans;
    for (int i = 0; i < n; ++i)
        ans.push_back(graph.con[i]);
    return ans;
}

Compilation message (stderr)

beechtree.cpp: In function 'int dfs(int)':
beechtree.cpp:72:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |     for (int i = 0; i < graph.srt[u].size() - 1; ++i)
      |                     ~~^~~~~~~~~~~~~~~~~~~~~~~~~

• 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: 14 / 14
• Subtask 7: 0 / 12
• Subtask 8: 0 / 17
• Subtask 9: 0 / 12