Submission #1068649

#	Time	Username	Problem	Language	Result	Execution time	Memory
1068649		parsadox2	Beech Tree (IOI23_beechtree)	C++17	22 / 100	71 ms	42140 KiB

beechtree

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

#define F first
#define S second

using namespace std;

const int N = 2e5 + 10;
int n , col[N] , m , sbt[N] , is_path[N] , cnt[N] , dis[N];
vector <int> adj[N];
vector <int> all , p;
bool bad[N] , mark[N];

void Dfs(int v)
{
    sbt[v] = 1;
    dis[v] = 0;
    for(auto u : adj[v])
    {
        Dfs(u);
        sbt[v] += sbt[u];
        bad[v] |= bad[u];
        dis[v] = max(dis[v] , dis[u] + 1);
    }
    if(adj[v].size() == 1)
    {
        int c = adj[v][0];
        if(sbt[c] == 1)
            is_path[v] = col[c];
        else if(col[c] == is_path[c])
            is_path[v] = col[c];
        else
            is_path[v] = -1;
    }
    else if(adj[v].size() > 1)
    {
        is_path[v] = -1;
    }
    vector <int> vec;
    for(auto u : adj[v])
        vec.push_back(col[u]);
    sort(vec.begin() , vec.end());
    for(int i = 1 ; i < vec.size() ; i++)  if(vec[i] == vec[i - 1])
        bad[v] = true;
}

void Dfs_all(int v)
{
    all.push_back(v);
    cnt[col[v]] = 0;
    for(auto u : adj[v])
        Dfs_all(u);
}

bool cmp(pair<int , int> aa , pair<int , int> bb)
{
    if(cnt[aa.F] != cnt[bb.F])
        return cnt[aa.F] < cnt[bb.F];
    return aa.F < bb.F;
}


bool Solve(int v)
{
    //cout << v << " : " << endl;
    all.clear();
    Dfs_all(v);
    sort(all.begin() , all.end());
    vector <int> vec , all_col;
    int cnt_root = 0;
    vector <pair<int , int>> check;
    for(int i = 1 ; i < all.size() ; i++)
    {
        int now = all[i];
        all_col.push_back(col[now]);
        if(p[now] != v)
        {
            cnt[col[now]]++;
            check.push_back(make_pair(col[now] , p[now]));
            mark[p[now]] = false;
        }
    }
    sort(all_col.begin() , all_col.end());
    all_col.resize(unique(all_col.begin() , all_col.end()) - all_col.begin());
    if(all_col.size() != adj[v].size())
        return false;
    all_col.clear();
    for(auto u : check)
        all_col.push_back(u.F);
    sort(all_col.begin() , all_col.end());
    all_col.resize(unique(all_col.begin() , all_col.end()) - all_col.begin());
    sort(check.begin() , check.end() , cmp);
    int las = -1 , num = all_col.size() + 1;
    for(auto u : check)
    {
        if(u.F != las)
        {
            las = u.F;
            num--;
        }
        //cout << las << " " << num << " " << u.S << endl;
        if((int)adj[u.S].size() < num)
        {
            //cout << "WTF " << endl;
            return false;
        }
    }
    return true;
}

vector<int> beechtree(int nn, int mm, vector<int> P, vector<int> C)
{
    n = nn;  
    m = mm;
    p = P;
    for(int i = 1 ; i < n ; i++)
    {
        adj[P[i]].push_back(i);
        col[i] = C[i];
    }
    Dfs(0);
    vector <int> res(n , 0);
    for(int i = 0 ; i < n ; i++)
    {
        if(is_path[i] != -1)
        {
            res[i] = true;
            continue;
        }
        if(bad[i] || dis[i] >= 3)
        {
            continue;
        }
        res[i] = Solve(i);
    }
    return res;
}

Compilation message (stderr)

beechtree.cpp: In function 'void Dfs(int)':
beechtree.cpp:44:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     for(int i = 1 ; i < vec.size() ; i++)  if(vec[i] == vec[i - 1])
      |                     ~~^~~~~~~~~~~~
beechtree.cpp: In function 'bool Solve(int)':
beechtree.cpp:73:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |     for(int i = 1 ; i < all.size() ; i++)
      |                     ~~^~~~~~~~~~~~
beechtree.cpp:71:9: warning: unused variable 'cnt_root' [-Wunused-variable]
   71 |     int cnt_root = 0;
      |         ^~~~~~~~

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