Question

the size field now has the number of elements for the trees array of the class tree. a null reference to this array has already been declared at the class level. it is time to give the trees array dimension.

Answer 1

C++ : // CPP program to construct binary

// tree from given array in level

// order fashion Tree Node

#include <bits/stdc++.h>

using namespace std;

/* A binary tree node has data,

pointer to left child and a

pointer to right child */

struct Node

{

int data;

Node* left, * right;

};

/* Helper function that allocates a

new node */

Node* newNode(int data)

{

Node* node = (Node*)malloc(sizeof(Node));

node->data = data;

node->left = node->right = NULL;

return (node);

}

// Function to insert nodes in level order

Node* insertLevelOrder(int arr[],

int i, int n)

{

Node *root = nullptr;

// Base case for recursion

if (i < n)

{

root = newNode(arr[i]);

// insert left child

root->left = insertLevelOrder(arr,

2 * i + 1, n);

// insert right child

root->right = insertLevelOrder(arr,

2 * i + 2, n);

}

return root;

}

// Function to print tree nodes in

// InOrder fashion

void inOrder(Node* root)

{

if (root != NULL)

{

inOrder(root->left);

cout << root->data <<" ";

inOrder(root->right);

}

}

// Driver program to test above function

int main()

{

int arr[] = { 1, 2, 3, 4, 5, 6, 6, 6, 6 };

int n = sizeof(arr)/sizeof(arr[0]);

Node* root = insertLevelOrder(arr, 0, n);

inOrder(root);

}