Insert a node in a BST Java

PROGRAM TO INSERT A NODE IN BINARY SEARCH TREE




class BinarySearchTree {

 

    /* Class containing left

       and right child of current node

     * and key value*/

    class Node

    {

        int key;

        Node left, right;

 

        public Node(int item)

        {

            key = item;

            left = right = null;

        }

    }

 

    // Root of BST

    Node root;

 

    // Constructor

    BinarySearchTree()

    {

         root = null;

    }

 

    // This method mainly calls insertRec()

    void insert(int key)

    {

         root = insertRec(root, key);

    }

 

    /* A recursive function to

       insert a new key in BST */

    Node insertRec(Node root, int key)

    {

 

        /* If the tree is empty,

           return a new node */

        if (root == null)

        {

            root = new Node(key);

            return root;

        }

 

        /* Otherwise, recur down the tree */

        if (key < root.key)

            root.left = insertRec(root.left, key);

        else if (key > root.key)

            root.right = insertRec(root.right, key);

 

        /* return the (unchanged) node pointer */

        return root;

    }

 

    // This method mainly calls InorderRec()

    void inorder()

    {

         inorderRec(root);

    }

 

    // A utility function to

    // do inorder traversal of BST

    void inorderRec(Node root)

    {

        if (root != null) {

            inorderRec(root.left);

            System.out.println(root.key);

            inorderRec(root.right);

        }

    }

 

    // Driver Code

    public static void main(String[] args)

    {

        BinarySearchTree tree = new BinarySearchTree();

 

        /* Let us create following BST

              50

           /     \

          30      70

         /  \    /  \

       20   40  60   80 */

        tree.insert(50);

        tree.insert(30);

        tree.insert(20);

        tree.insert(40);

        tree.insert(70);

        tree.insert(60);

        tree.insert(80);

 

        // print inorder traversal of the BST

        tree.inorder();

    }

}




OUTPUT:

20 
30 
40 
50 
60 
70 
80

CREDITS: https://www.geeksforgeeks.org/binary-search-tree-set-1-search-and-insertion/