helperFunctions.h

#ifndef HELPERFUNCTIONS_H
#define HELPERFUNCTIONS_H

#include <bits/stdc++.h>

using namespace std;

struct ListNode {
  int val;
  ListNode *next;
  ListNode() : val(0), next(nullptr) {}
  ListNode(int x) : val(x), next(nullptr) {}
  ListNode(int x, ListNode *next) : val(x), next(next) {}
};

struct TreeNode {
  int val;
  TreeNode *left;
  TreeNode *right;
  TreeNode() : val(0), left(nullptr), right(nullptr) {}
  TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
  TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
};

template <typename T> void display2DVector(const vector<vector<T>> &arr);

template <typename T> void displayVector(const vector<T> &arr);

TreeNode *createDefaultTree();

#include "helperFunctions.cpp"

#endif