Question

I have written a code for deleting all elements of tree.
Need suggestions for following:

1. In reverseTreeStack method, Can I design without using stack method parameter?
2. Can I design the entire code in 1 method with better design?

UPDATE : Changed return type of reverseTreeStack to void.Removed additional variable for stack.

    public class DeleteTree {

    public static void deleteTree(BinaryTreeNode root)
    {       
        Stack stack = new Stack();
        reverseTreeStack(stack, root);
        while (!stack.isEmpty())
        {
            BinaryTreeNode node = (BinaryTreeNode)stack.pop();
            System.out.println("---------Deleting----------->" + node.getData());
            node = null;
        }
    }

    public static void reverseTreeStack(Stack stack,BinaryTreeNode root)
    {
        if (root != null)
        {
            stack.push(root);   
            reverseTreeStack(stack,root.getLeft());
            reverseTreeStack(stack, root.getRight());
        }
    }
}

Answer 1

1) I think you can kill the return value and make it a void method as you are directly manipulating the stack. So just do

 Stack stack = new Stack();
 reverseTreeStack(stack, root);

 // Now just use stack

2) Don’t condense things into one method. Breaking things out into more methods will make your code easier to navigate and understand. The less each function is responsible for, the more sense it will make to someone reading it.