Insertion in a Binary Tree (Level Order) in Java

March 22, 2023

Insertion in Binary Tree

Insertion in Binary Tree is being discussed in this article. A binary tree can be defined as a finite set of elements, which can either be empty or have at most two children. Given a tree and a key, add a node in the first available node in the tree. After adding the node, print the level order traversal. 

insertion in binary tree

Binary Tree

  • A Binary Tree is a data structure with maximum of two children for each parent.
  • Level Order Traversal is an example Of Breadth First Search algorithm.
  • Level order is a traversal in which each node is visited in the level before we move to a lower level.
  • Queues are used to find the level order traversal.
Insertion in Binary Tree (Level Order)
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Searching in a Binary Search Tree

AVL Tree Insertion

Depth First Traversals

Level Order Traversal

Construct Tree from given Inorder and Preorder traversals

Algorithm

  • Iterate level order traversal of the given tree using queue.
  • If we find a node whose left child is empty, we make new key as left child of the node.
  • Else if we find a node whose right child is empty, we make the new key as right child. 
  • Keep traversing the tree until we find a node whose wither left or right child is empty.
Run 
import java.util.*;
class Node
{
  int value;
  Node left, right;


    Node (int value)
  {
    this.value = value;
    left = right = null;
  }
}

class Main
{
  static Node root;
  //static Node temp=root;
  public static void inorder (Node ptr)
  {
    if (ptr == null)
      return;
    inorder (ptr.left);

    System.out.print (ptr.value + " ");
    inorder (ptr.right);
  }

  public static void insert (Node ptr, int item)
  {
    if (ptr == null)
      {
	root = new Node (item);
	return;
      }
    Queue < Node > que = new LinkedList < Node > ();
    que.add (ptr);

    while (!que.isEmpty ())
      {
	ptr = que.peek ();
	que.remove ();
	if (ptr.left == null)
	  {
	    ptr.left = new Node (item);
	    break;
	  }
	else
	  que.add (ptr.left);

	if (ptr.right == null)
	  {
	    ptr.right = new Node (item);
	    break;
	  }
	else
	  que.add (ptr.right);
      }
  }


  public static void main (String[]args)
  {
    Node root = new Node (10);
    root.left = new Node (20);
    root.left.left = new Node (30);
    root.right = new Node (40);
    root.right.left = new Node (50);
    root.right.right = new Node (60);

    System.out.println ("Inorder Traversal before Insertion: ");
    inorder (root);

    int item = 7;
    insert (root, item);

    System.out.println ("\nInorder Traversal after insertion");

    inorder (root);
  }
}

Output:

Inorder Traversal before Insertion: 
30 20 10 50 40 60 
Inorder Traversal after insertion
30 20 70 10 50 40 60

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Introduction to Trees

Binary Trees

Binary Search Trees

Traversals

  • Traversal in Trees
  • Tree Traversals: Breadth-First Search (BFS) : C | C++ | Java
  • Tree Traversals: Depth First Search (DFS) : C | C++ | Java
  • Construct a Binary Tree from Postorder and Inorder

B – Trees

AVL Trees

  • AVL Trees
    • AVL Trees: Introduction
    • AVL Tree Insertion :  C | C++ | Java
    • AVL Tree Deletion : C | C++ | Java
    • Insertion in a Binary Tree (Level Order) – C | C++ | Java
    • Searching in Binary Tree – C | C++ | Java
    • Searching in a Binary Search Tree – C | C++ | Java

Complete Programs for Trees

  • Depth First Traversals – C | C++ | Java
  • Level Order Traversal – C | C++ | Java
  • Construct Tree from given Inorder and Preorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Inorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Preorder traversal – C | C++ | Java
  • Find size of the Binary tree – C | C++ | Java
  • Find the height of binary tree – C | C++ | Java
  • Find maximum in binary tree – C | C++ | Java
  • Check whether two tree are identical- C| C++| Java
  • Spiral Order traversal of Tree- C | C++| Java
  • Level Order Traversal LIne by Line – C | C++| Java
  • Hand shaking lemma and some Impotant Tree Properties.
  • Check If binary tree if Foldable or not.- C| C++| Java
  • check whether tree is Symmetric  C| C++| Java.
  • Check for Children-Sum in Binary Tree- C|C++| Java
  • Sum of all nodes in Binary Tree- C | C++ | Java
  • Lowest Common Ancestor in Binary Tree. C | C++ | Java

Introduction to Trees

Binary Trees

Binary Search Trees

Traversals

  • Traversal in Trees
  • Tree Traversals: Breadth-First Search (BFS) : C | C++ | Java
  • Tree Traversals: Depth First Search (DFS) : C | C++ | Java
  • Construct a Binary Tree from Postorder and Inorder

B – Trees

AVL Trees

  • AVL Trees
    • AVL Trees: Introduction
    • AVL Tree Insertion : C | C++ | Java
    • AVL Tree Deletion : C | C++ | Java
    • Insertion in a Binary Tree (Level Order) – C | C++ | Java
    • Searching in Binary Tree – C | C++ | Java
    • Searching in a Binary Search Tree – C | C++ | Java

Complete Programs for Trees

  • Depth First Traversals – C | C++ | Java
  • Level Order Traversal – C | C++ | Java
  • Construct Tree from given Inorder and Preorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Inorder traversals – C | C++ | Java
  • Construct Tree from given Postorder and Preorder traversal – C | C++ | Java
  • Find size of the Binary tree – C | C++ | Java
  • Find the height of binary tree – C | C++ | Java
  • Find maximum in binary tree – C | C++ | Java
  • Check whether two tree are identical- C| C++| Java
  • Spiral Order traversal of Tree- C | C++| Java
  • Level Order Traversal Line by Line – C | C++| Java
  • Hand shaking lemma and some Impotant Tree Properties.
  • Check If binary tree if Foldable or not.- C| C++| Java
  • check whether tree is Symmetric – C| C++| Java.
  • Check for Children-Sum in Binary Tree- C|C++| Java
  • Sum of all nodes in Binary Tree- C | C++ | Java
  • Lowest Common Ancestor in Binary Tree- C | C++ | Java