Replace every node with depth in N-ary Generic Tree
Given an array arr[] representing a Generic(N-ary) tree. The task is to replace the node data with the depth(level) of the node. Assume level of root to be 0.
Array Representation: The N-ary tree is serialized in the array arr[] using level order traversal as described below:
- The input is given as a level order traversal of N-ary Tree.
- The first element of the array arr[] is the root node.
- Then, followed by a number N, which denotes the number of children of the previous node. Value zero denotes Null Node.
Examples:
Input: arr[] = { 10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0 }
Below is the N-ary Tree of the above array level order traversal:
Output:
Below is the representation of the above output:
Input: arr[] = {1, 3, 2, 3, 4, 2, 5, 6, 0, 0, 2, 8, 9, 0}
Below is the N-ary Tree of the above array level order traversal:
Output:
Below is the representation of the above output:
Approach:
- Traverse the tree starting from root.
- While traversing pass depth of node as a parameter.
- Track depth by passing it as 0 for root and (1 + current level) for children.
Below is the implementation of the above approach:
// C++ program to implement node with
// it's depth value
#include <bits/stdc++.h>
using namespace std;
// Treenode class using template
template <typename T>
class TreeNode {
public:
// To store node value
T data;
// Pointer to TreeNode to store
// the child node
vector<TreeNode<T>*> children;
// Constructor to assign data
// to node
TreeNode(T data)
{
this->data = data;
}
// Destructors to delete a node
~TreeNode()
{
for (int i = 0;
i < children.size(); i++) {
delete children[i];
}
}
};
// Function to take input level wise
// i.e., in level order traversal
TreeNode<int>* takeInputLevelWise(int arr[])
{
int idx = 1;
// Input root
int rootData = arr[0];
// Initialize tree with a root node
TreeNode<int>* root
= new TreeNode<int>(rootData);
// Initialise queue for appending
// node as a child of parent in
// N-ary tree
queue<TreeNode<int>*> pendingNodes;
// Push the root node in queue
pendingNodes.push(root);
// While queue is not empty append
// child to the root
while (pendingNodes.size() != 0) {
// Take the first node
TreeNode<int>* front
= pendingNodes.front();
pendingNodes.pop();
// Input number of child
int numChild = arr[idx];
idx++;
for (int i = 0; i < numChild; i++) {
int childData = arr[idx];
idx++;
// Make child Node
TreeNode<int>* child
= new TreeNode<int>(childData);
// Append child node to
// it's parent
front->children.push_back(child);
pendingNodes.push(child);
}
}
return root;
}
// Function to print each node data
// in level order
void printLevelATNewLine(TreeNode<int>* root)
{
queue<TreeNode<int>*> q;
q.push(root);
q.push(NULL);
while (!q.empty()) {
TreeNode<int>* first = q.front();
q.pop();
if (first == NULL) {
if (q.empty()) {
break;
}
cout << endl;
q.push(NULL);
continue;
}
cout << first->data << " ";
for (int i = 0;
i < first->children.size(); i++) {
q.push(first->children[i]);
}
}
}
// Helper function to replace the
// node data with their level value
void helper(TreeNode<int>* root,
int depth)
{
// Replace the node data with
// it's depth
root->data = depth;
for (int i = 0;
i < root->children.size(); i++) {
helper(root->children[i], depth + 1);
}
}
// Function to replace with depth
void replaceWithDepthValue(TreeNode<int>* root)
{
helper(root, 0);
}
// Driver Code
int main()
{
// Given level order traversal in
// the array arr[]
int arr[] = { 1, 3, 2, 3, 4, 2, 5, 6, 0, 0, 2, 8, 9, 0};
// Initialise Tree
TreeNode<int>* root;
root = takeInputLevelWise(arr);
// Function call to replace with
// depth value
replaceWithDepthValue(root);
// Function call to print
// in level order
printLevelATNewLine(root);
return 0;
}
// Java program to replace node with
// it's depth value
// Importing classes and interface
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Queue;
class GFG {
// TreeNode class
static class TreeNode<T> {
// To store node value
T data;
// List of TreeNode to store
// the child nodes
ArrayList<TreeNode<T> > children;
// Constructor to assign data to node
TreeNode(T data)
{
this.data = data;
children = new ArrayList<TreeNode<T> >();
}
}
// Function to take input level wise
// i.e., in level order traversal
static TreeNode<Integer> takeInputLevelWise(int arr[])
{
int idx = 1;
// Input root
int rootData = arr[0];
// Initialize tree with a root node
TreeNode<Integer> root
= new TreeNode<Integer>(rootData);
// Initialize queue for appending
// node as a child of parent in
// N-ary tree
Queue<TreeNode<Integer> > pendingNodes
= new LinkedList<TreeNode<Integer> >();
// Push the root node in queue
pendingNodes.add(root);
// While queue is not empty append
// child to the node
while (pendingNodes.size() != 0) {
// Take the first node
TreeNode<Integer> front = pendingNodes.peek();
pendingNodes.poll();
// Input number of its child
int numChild = arr[idx];
idx++;
for (int i = 0; i < numChild; i++) {
int childData = arr[idx];
idx++;
// Make child Node
TreeNode<Integer> child
= new TreeNode<Integer>(childData);
// Append child node to
// it's parent
front.children.add(child);
pendingNodes.add(child);
}
}
return root;
}
// Function to print each node data
// in level order
static void printLevelATNewLine(TreeNode<Integer> root)
{
Queue<TreeNode<Integer> > q
= new LinkedList<TreeNode<Integer> >();
q.add(root);
q.add(null);
while (!q.isEmpty()) {
TreeNode<Integer> first = q.peek();
q.poll();
if (first == null) {
// If there is no more nodes
if (q.isEmpty()) {
break;
}
// All the nodes of current level are
// visited
System.out.println();
q.add(null);
continue;
}
System.out.print(first.data + " ");
// Append current node's child to queue
for (int i = 0; i < first.children.size();
i++) {
q.add(first.children.get(i));
}
}
}
// Helper function to replace the
// node data with their level value
static void helper(TreeNode<Integer> root, int depth)
{
// Replace the node data with
// it's depth
root.data = depth;
for (int i = 0; i < root.children.size(); i++) {
helper(root.children.get(i), depth + 1);
}
}
// Function to replace with depth
static void
replaceWithDepthValue(TreeNode<Integer> root)
{
helper(root, 0);
}
// Driver Code
public static void main(String[] args)
{
// Given level order traversal in
// the array arr[]
int arr[]
= { 10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0 };
// Initialise Tree
TreeNode<Integer> root;
root = takeInputLevelWise(arr);
// Function call to replace with
// depth value
replaceWithDepthValue(root);
// Function call to print
// in level order
printLevelATNewLine(root);
}
}
// This code is contributed by jainlovely450
# Python code for the above approach
from typing import List, Tuple
# TreeNode class
class TreeNode:
# To store node value
data: int
# List of TreeNode to store
# the child nodes
children: List['TreeNode']
# Constructor to assign data to node
def __init__(self, data: int):
self.data = data
self.children = []
# Function to take input level wise
# i.e., in level order traversal
def take_input_level_wise(arr: List[int]) -> TreeNode:
idx = 1
# Input root
root_data = arr[0]
# Initialize tree with a root node
root = TreeNode(root_data)
# Initialize queue for appending
# node as a child of parent in
# N-ary tree
pending_nodes = [root]
# While queue is not empty append
# child to the node
while pending_nodes:
# Take the first node
front = pending_nodes[0]
pending_nodes = pending_nodes[1:]
# Input number of its child
num_child = arr[idx]
idx += 1
for i in range(num_child):
child_data = arr[idx]
idx += 1
# Make child Node
child = TreeNode(child_data)
# Append child node to
# it's parent
front.children.append(child)
pending_nodes.append(child)
return root
# Function to print each node data
# in level order
def print_level_at_new_line(root: TreeNode):
q = [root]
q.append(None)
while q:
first = q[0]
q = q[1:]
if first is None:
# If there is no more nodes
if not q:
break
# All the nodes of current level are
# visited
print()
q.append(None)
continue
print(first.data, end=' ')
# Append current node's child to queue
for i in range(len(first.children)):
q.append(first.children[i])
# Helper function to replace the
# node data with their level value
def helper(root: TreeNode, depth: int):
# Replace the node data with
# it's depth
root.data = depth
for i in range(len(root.children)):
helper(root.children[i], depth + 1)
# Function to replace with depth
def replace_with_depth_value(root: TreeNode):
helper(root, 0)
# Driver Code
if __name__ == '__main__':
# Given level order traversal in
# the array arr[]
arr = [10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0]
# Initialise Tree
root = take_input_level_wise(arr)
# Function call to replace with
# depth value
replace_with_depth_value(root)
# Print the tree in level order
print_level_at_new_line(root)
# This code is contributed by Potta Lokesh
using System;
using System.Collections.Generic;
// Class to represent a node with data and its children in
// N-ary tree
class TreeNode<T> {
public T Data
{
get;
set;
}
public List<TreeNode<T> > Children
{
get;
set;
}
public TreeNode(T data)
{
this.Data = data;
this.Children = new List<TreeNode<T> >();
}
}
class GFG {
static void Main(string[] args)
{
// Input level order data
int[] arr
= { 10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0 };
// Initialize Tree with root node
var root = TakeInputLevelWise(arr);
// Replace the node data with their depth value
ReplaceWithDepthValue(root, 0);
// Print level order
PrintLevelAtNewLine(root);
}
// Function to take input level wise
static TreeNode<int> TakeInputLevelWise(int[] arr)
{
int idx = 1;
// Input root data
int rootData = arr[0];
var root = new TreeNode<int>(rootData);
// Initialise queue for appending node as a child of
// parent
var pendingNodes = new Queue<TreeNode<int> >();
// Push the root node in queue
pendingNodes.Enqueue(root);
// While queue is not empty append child to the root
while (pendingNodes.Count != 0) {
// Take the first node
var front = pendingNodes.Dequeue();
// Input number of children
int numChild = arr[idx];
idx++;
for (int i = 0; i < numChild; i++) {
int childData = arr[idx];
idx++;
// Make child node
var child = new TreeNode<int>(childData);
// Append child node to its parent
front.Children.Add(child);
pendingNodes.Enqueue(child);
}
}
return root;
}
// Function to print level order
static void PrintLevelAtNewLine(TreeNode<int> root)
{
var q = new Queue<TreeNode<int> >();
q.Enqueue(root);
q.Enqueue(null);
while (q.Count != 0) {
var first = q.Dequeue();
if (first == null) {
if (q.Count == 0) {
break;
}
Console.WriteLine();
q.Enqueue(null);
continue;
}
Console.Write(first.Data + " ");
foreach(var child in first.Children)
{
q.Enqueue(child);
}
}
}
// Function to replace node data with their depth value
static void ReplaceWithDepthValue(TreeNode<int> root,
int depth)
{
root.Data = depth;
foreach(var child in root.Children)
{
ReplaceWithDepthValue(child, depth + 1);
}
}
}
//This Code is Contributed by chinmaya121221
// JavaScript program to replace node with it's depth value
// TreeNode class
class TreeNode {
constructor(data) {
// To store node value
this.data = data;
// List of TreeNode to store the child nodes
this.children = [];
}
}
// Function to take input level wise i.e., in level order traversal
function takeInputLevelWise(arr) {
let idx = 1;
// Input root
let rootData = arr[0];
// Initialize tree with a root node
const root = new TreeNode(rootData);
// Initialize queue for appending node as a child of parent in N-ary tree
const pendingNodes = [];
// Push the root node in queue
pendingNodes.push(root);
// While queue is not empty append child to the node
while (pendingNodes.length !== 0) {
// Take the first node
const front = pendingNodes.shift();
// Input number of its child
const numChild = arr[idx];
idx++;
for (let i = 0; i < numChild; i++) {
const childData = arr[idx];
idx++;
// Make child Node
const child = new TreeNode(childData);
// Append child node to it's parent
front.children.push(child);
pendingNodes.push(child);
}
}
return root;
}
// Function to print each node data in level order
function printLevelATNewLine(root) {
const q = [];
q.push(root);
q.push(null);
while (q.length !== 0) {
const first = q.shift();
if (first === null) {
// If there is no more nodes
if (q.length === 0) {
break;
}
// All the nodes of current level are visited
console.log("<br>");
q.push(null);
continue;
}
console.log(first.data + " ");
// Append current node's child to queue
for (let i = 0; i < first.children.length; i++) {
q.push(first.children[i]);
}
}
}
// Helper function to replace the node data with their level value
function helper(root, depth) {
// Replace the node data with it's depth
root.data = depth;
for (let i = 0; i < root.children.length; i++) {
helper(root.children[i], depth + 1);
}
}
// Function to replace with depth
function replaceWithDepthValue(root) {
helper(root, 0);
}
// Given level order traversal in the array arr[]
const arr = [10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0];
// Initialise Tree
let root = takeInputLevelWise(arr);
// Function call to replace with depth value
replaceWithDepthValue(root);
// Function call to print in level order
printLevelATNewLine(root);
// This code is contributed by sankar.
Output
0 1 1 1 2 2 3 3
Time Complexity: O(N), where N is the number of nodes in Tree.
Auxiliary Space: O(N), where N is the number of nodes in Tree.
Another Approach: We can also replace the node’s value with its depth while creating the tree. We are traversing the array level wise which means that nodes currently present in the queue are of the same depth. As we append its child nodes to the queue, they will be present in the next level. We can initialize a variable as current depth equal to 1 and when we create child node we can assign its value to current depth level. After traversing all the nodes present in the current level we will increment current depth level by 1.
// C++ program to implement node with
// it's depth value
#include <bits/stdc++.h>
using namespace std;
// Treenode class using template
template <typename T> class TreeNode {
public:
// To store node value
T data;
// Pointer to TreeNode to store
// the child node
vector<TreeNode<T>*> children;
// Constructor to assign data
// to node
TreeNode(T data) { this->data = data; }
// Destructors to delete a node
~TreeNode()
{
for (int i = 0; i < children.size(); i++) {
delete children[i];
}
}
};
// Function to take input level wise
// i.e., in level order traversal
TreeNode<int>* takeInputLevelWise(int arr[])
{
int idx = 1;
int depthLevel = 1;
// Initialize tree with a root node
// with depth 0
TreeNode<int>* root = new TreeNode<int>(0);
// Initialise queue for appending
// node as a child of parent in
// N-ary tree
queue<TreeNode<int>*> pendingNodes;
// Push the root node in queue
pendingNodes.push(root);
// While queue is not empty append
// child to the node
while (pendingNodes.size() != 0) {
// Number of nodes present in the current level
int size = pendingNodes.size();
while (size > 0) {
// Take the first node
TreeNode<int>* front = pendingNodes.front();
pendingNodes.pop();
// Input number of its child
int numChild = arr[idx];
idx++;
for (int i = 0; i < numChild; i++) {
idx++;
// Make child Node and assign its data
// value equal to depthLevel
TreeNode<int>* child
= new TreeNode<int>(depthLevel);
// Append child node to
// it's parent
front->children.push_back(child);
pendingNodes.push(child);
}
size--;
}
// Increment depth level
depthLevel++;
}
return root;
}
// Function to print each node data
// in level order
void printLevelATNewLine(TreeNode<int>* root)
{
queue<TreeNode<int>*> q;
q.push(root);
q.push(NULL);
while (!q.empty()) {
TreeNode<int>* first = q.front();
q.pop();
if (first == NULL) {
// If there is no more nodes to visit
if (q.empty()) {
break;
}
// All the nodes of current level are visited
cout << endl;
q.push(NULL);
continue;
}
cout << first->data << " ";
// Append current node's child to queue
for (int i = 0; i < first->children.size(); i++) {
q.push(first->children[i]);
}
}
}
// Driver Code
int main()
{
// Given level order traversal in
// the array arr[]
int arr[]
= { 10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0 };
// Initialise Tree
TreeNode<int>* root;
root = takeInputLevelWise(arr);
// Function call to print
// in level order
printLevelATNewLine(root);
return 0;
}
// This code is contributed by jainlovely450
// Java program to implement node with
// it's depth value
// Importing classes and interface
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Queue;
public class GFG {
// TreeNode class
static class TreeNode<T> {
// To store node value
T data;
// List of TreeNode to store
// the child nodes
ArrayList<TreeNode<T> > children;
// Constructor to assign data to node
TreeNode(T data)
{
this.data = data;
children = new ArrayList<TreeNode<T> >();
}
}
// Function to take input level wise
// i.e., in level order traversal and
// assign value of node equal to its depth
static TreeNode<Integer> takeInputLevelWise(int arr[])
{
int idx = 1;
int depthLevel = 1;
// Initialize tree with a root node
// with depth 0
TreeNode<Integer> root = new TreeNode<Integer>(0);
// Initialize queue for appending
// node as a child of parent in
// N-ary tree
Queue<TreeNode<Integer> > pendingNodes
= new LinkedList<TreeNode<Integer> >();
// Push the root node in queue
pendingNodes.add(root);
// While queue is not empty append
// child to the node
while (!pendingNodes.isEmpty()) {
// Number of nodes present in the current level
int size = pendingNodes.size();
while (size > 0) {
TreeNode<Integer> front
= pendingNodes.peek();
pendingNodes.poll();
// Input number of child
int numChild = arr[idx];
idx++;
for (int i = 0; i < numChild; i++) {
idx++;
// Make child Node and assign its data
// value equal to depthLevel
TreeNode<Integer> child
= new TreeNode<Integer>(depthLevel);
// Append child node to
// it's parent
front.children.add(child);
pendingNodes.add(child);
}
size--;
}
// Increment depth level
depthLevel++;
}
return root;
}
// Function to print each node data
// in level order
static void printLevelATNewLine(TreeNode<Integer> root)
{
Queue<TreeNode<Integer> > q
= new LinkedList<TreeNode<Integer> >();
q.add(root);
q.add(null);
while (!q.isEmpty()) {
TreeNode<Integer> first = q.peek();
q.poll();
if (first == null) {
// If there is no more nodes to visit
if (q.isEmpty()) {
break;
}
// All the nodes of current level are
// visited
System.out.println();
q.add(null);
continue;
}
System.out.print(first.data + " ");
// Append current node's child to queue
for (int i = 0; i < first.children.size();
i++) {
q.add(first.children.get(i));
}
}
}
// Driver Code
public static void main(String[] args)
{
// Given level order traversal in
// the array arr[]
int arr[]
= { 10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0 };
// Initialize Tree
TreeNode<Integer> root;
root = takeInputLevelWise(arr);
// Function call to print
// in level order
printLevelATNewLine(root);
}
}
// This code is contributed by jainlovely450
# Python code
# TreeNode class
class TreeNode:
# To store node value
def __init__(self, data):
self.data = data
# List of TreeNode to store
# the child nodes
self.children = []
# Function to take input level wise
# i.e., in level order traversal and
# assign value of node equal to its depth
def takeInputLevelWise(arr):
idx = 1
depthLevel = 1
# Initialize tree with a root node
# with depth 0
root = TreeNode(0)
# Initialize queue for appending
# node as a child of parent in
# N-ary tree
pendingNodes = []
pendingNodes.append(root)
# While queue is not empty append
# child to the node
while pendingNodes:
# Number of nodes present in the current level
size = len(pendingNodes)
while size > 0:
front = pendingNodes[0]
pendingNodes.pop(0)
# Input number of child
numChild = arr[idx]
idx += 1
for i in range(numChild):
idx += 1
# Make child Node and assign its data
# value equal to depthLevel
child = TreeNode(depthLevel)
# Append child node to
# it's parent
front.children.append(child)
pendingNodes.append(child)
size -= 1
# Increment depth level
depthLevel += 1
return root
# Function to print each node data
# in level order
def printLevelATNewLine(root):
q = []
q.append(root)
q.append(None)
while q:
first = q[0]
q.pop(0)
if first is None:
# If there is no more nodes to visit
if not q:
break
# All the nodes of current level are
# visited
print()
q.append(None)
continue
print(first.data, end=" ")
# Append current node's child to queue
for i in range(len(first.children)):
q.append(first.children[i])
# Driver Code
if __name__ == '__main__':
# Given level order traversal in
# the array arr[]
arr = [10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0]
# Initialize Tree
root = takeInputLevelWise(arr)
# Function call to print
# in level order
printLevelATNewLine(root)
// C# program to implement node with it's depth value
using System;
using System.Collections.Generic;
public class GFG {
// TreeNode class
class TreeNode<T> {
// To store node value
public T data;
// List of TreeNode to store
// the child nodes
public List<TreeNode<T> > children;
// Constructor to assign data to node
public TreeNode(T data)
{
this.data = data;
children = new List<TreeNode<T> >();
}
}
// Function to take input level wise i.e., in level
// order traversal and assign value of node equal to its
// depth
static TreeNode<int> takeInputLevelWise(int[] arr)
{
int idx = 1;
int depthLevel = 1;
// Initialize tree with a root node with depth 0
TreeNode<int> root = new TreeNode<int>(0);
// Initialize queue for appending node as a child of
// parent in N-ary tree
Queue<TreeNode<int> > pendingNodes
= new Queue<TreeNode<int> >();
// Push the root node in queue
pendingNodes.Enqueue(root);
// While queue is not empty append child to the node
while (pendingNodes.Count != 0) {
// Number of nodes present in the current level
int size = pendingNodes.Count;
while (size > 0) {
TreeNode<int> front = pendingNodes.Peek();
pendingNodes.Dequeue();
// Input number of child
int numChild = arr[idx];
idx++;
for (int i = 0; i < numChild; i++) {
idx++;
// Make child Node and assign its data
// value equal to depthLevel
TreeNode<int> child
= new TreeNode<int>(depthLevel);
// Append child node to it's parent
front.children.Add(child);
pendingNodes.Enqueue(child);
}
size--;
}
// Increment depth level
depthLevel++;
}
return root;
}
// Function to print each node data in level order
static void printLevelATNewLine(TreeNode<int> root)
{
Queue<TreeNode<int> > q
= new Queue<TreeNode<int> >();
q.Enqueue(root);
q.Enqueue(null);
while (q.Count != 0) {
TreeNode<int> first = q.Peek();
q.Dequeue();
if (first == null) {
// If there is no more nodes to visit
if (q.Count == 0) {
break;
}
// All the nodes of current level are
// visited
Console.WriteLine();
q.Enqueue(null);
continue;
}
Console.Write(first.data + " ");
// Append current node's child to queue
for (int i = 0; i < first.children.Count; i++) {
q.Enqueue(first.children[i]);
}
}
}
static public void Main()
{
// Code
// Given level order traversal in the array arr[]
int[] arr
= { 10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0 };
// Initialize Tree
TreeNode<int> root;
root = takeInputLevelWise(arr);
// Function call to print in level order
printLevelATNewLine(root);
}
}
// This code is contributed by karthik.
// JavaScript program to implement node with
// it's depth value
// TreeNode class
class TreeNode {
// To store node value
constructor(data) {
this.data = data;
// List of TreeNode to store
// the child nodes
this.children = [];
}
}
// Function to take input level wise
// i.e., in level order traversal and
// assign value of node equal to its depth
function takeInputLevelWise(arr) {
let idx = 1;
let depthLevel = 1;
// Initialize tree with a root node
// with depth 0
const root = new TreeNode(0);
// Initialize queue for appending
// node as a child of parent in
// N-ary tree
const pendingNodes = [];
// Push the root node in queue
pendingNodes.push(root);
// While queue is not empty append
// child to the node
while (pendingNodes.length !== 0) {
// Number of nodes present in the current level
let size = pendingNodes.length;
while (size > 0) {
const front = pendingNodes.shift();
// Input number of child
const numChild = arr[idx];
idx++;
for (let i = 0; i < numChild; i++) {
idx++;
// Make child Node and assign its data
// value equal to depthLevel
const child = new TreeNode(depthLevel);
// Append child node to
// it's parent
front.children.push(child);
pendingNodes.push(child);
}
size--;
}
// Increment depth level
depthLevel++;
}
return root;
}
// Function to print each node data
// in level order
function printLevelATNewLine(root) {
const q = [];
q.push(root);
q.push(null);
while (q.length !== 0) {
const first = q.shift();
if (first === null) {
// If there is no more nodes to visit
if (q.length === 0) {
break;
}
// All the nodes of current level are
// visited
console.log("<br>");
q.push(null);
continue;
}
console.log(first.data + " ");
// Append current node's child to queue
for (let i = 0; i < first.children.length; i++) {
q.push(first.children[i]);
}
}
console.log("<br>")
}
// Given level order traversal in
// the array arr[]
const arr = [10, 3, 20, 30, 40, 2, 40, 50, 0, 0, 0, 0];
// Initialize Tree
const root = takeInputLevelWise(arr);
// Function call to print
// in level order
printLevelATNewLine(root);
// This code is contributed by karthik.
Output
0 1 1 1 2 2
Time Complexity: O(N), where N is the number of nodes in Tree.
Auxiliary Space: O(N), where N is the number of nodes in Tree.