Submission #1071422

#	Time	Username	Problem	Language	Result	Execution time	Memory
1071422		KaleemRazaSyed	Beech Tree (IOI23_beechtree)	C++17	0 / 100	1625 ms	2097152 KiB

beechtree

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

using namespace std;

const int N = 200'000 + 10;
vector<int> child[N], subtree[N];
int n, h[N];

bool compare(int x, int y) {
  if(child[x].size() == child[y].size()) return h[x] < h[y];
  return child[x].size() > child[y].size();
}

bool check(int a, int b, vector<int> &C)
{
  set<int> st;
  for(int c : child[a])
    st.insert(C[c]);

  for(int c : child[b])
    if(st.find(C[c]) == st.end())
      return false;
  return true;
}

void dfs(int v, vector<int> &ans, vector<int> &C, vector<int> &P)
{
  subtree[v].push_back(v);
  if(child[v].empty())
    {
      ans[v] = 1;
      return;
    }
  
  for(int c : child[v])
    {
      h[c] = h[v] + 1;
      dfs(c, ans, C, P);
      for(int i : subtree[c])
	subtree[v].push_back(i);
      subtree[c].clear();
    }

  int cnt = 0;
  set<int> st;
  for(int c : child[v])
    {
      st.insert(C[c]);
      if(!child[c].empty())
	cnt++;
      if(ans[c] == 0)
	{
	  ans[v] = 0;
	  return;
	}
    }

  if(st.size() != child[v].size())
    {
      ans[v] = 0;
      return;
    }

  sort(subtree[v].begin(), subtree[v].end(), compare);
  
  bool ok = (subtree[v][0] == v);
  map<int,int> mp;
  for(int i = 1; i < subtree[v].size() && ok; i++)
    {
      int u = subtree[v][i];
      ok &= (subtree[v][mp[C[u]]] == P[u]);
      mp[C[u]]++;
    }
  ans[v] = ok;
}

vector<int> beechtree(int N, int M, vector<int> P, vector<int> C)
{
  for(int i = 1; i < N; i ++)
    child[P[i]].push_back(i);
  vector<int> ans(N);
  dfs(0, ans, C, P);
  return ans;
}

Compilation message (stderr)

beechtree.cpp: In function 'void dfs(int, std::vector<int>&, std::vector<int>&, std::vector<int>&)':
beechtree.cpp:69:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |   for(int i = 1; i < subtree[v].size() && ok; 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: 0 / 14
• Subtask 7: 0 / 12
• Subtask 8: 0 / 17
• Subtask 9: 0 / 12