Question

• Java - Data Structures

The method removeLeftmost() in a BinaryNode class is given below. Write this method in BinaryTree class.

→ *BinaryNode class

private class BinaryNode<T>

{

   private T data;

   private BinaryNode<T> leftChild;

   private BinaryNode<T> rightChild;

   ...

   // constructors

   // get and set methods

   // other methods

   /** removeLeftmost() - removes the leftmost node of the subtree rooted at this node */

   public BinaryNode<T> removeLeftmost()

   {

      if(leftChild == null)

         return rightChild

      else

         return leftChild.removeLeftmost();

   }

}

******************************************************************************************************************

--> BinaryTree class

public class BinaryTree<T>

{

   private BinaryNode<T> root;

   ...

   // Constructors

   // Get and Set methods

   // Other methods

   /** removeLeftmost()

     * use getLeftChild() or getRightChild() to access left/right child */

   private T removeLeftmost(BinaryNode<T> node)

   {

       // write code here

   }

}

Answer 1

class BinaryNode<T>

{

   private T data;

   private BinaryNode<T> leftChild;

   private BinaryNode<T> rightChild;

   // constructors

   // get and set methods

   // other methods

   /** removeLeftmost() - removes the leftmost node of the subtree rooted at this node */

   public BinaryNode<T> removeLeftmost()

   {

      if(leftChild == null)

         return rightChild;

      else

         return leftChild.removeLeftmost();

   }

}

//******************************************************************************************************************

public class BinaryTree<T>

{

   private BinaryNode<T> root;

   // Constructors

   // Get and Set methods

   // Other methods

   /** removeLeftmost()

     * use getLeftChild() or getRightChild() to access left/right child */

   private T removeLeftmost(BinaryNode<T> node)

   {
       if(node == null) return null;
       T val;
       if(node.getLeftChild() == null) {
           val = node.getData();
           root = node.getRightChild();
           return val;
       }
     
       while(node.getLeftChild().getLeftChild() != null) {
           node = node.getLeftChild();
       }
       val = node.getLeftChild().getData();
       node.setLeftChild(node.getLeftChild().getRightChild());
       return val;
   }

}