/*
This file is part of the algoviz@vt collection of algorithm
visualizations.

This program is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this distribution. If not, see
<http://www.gnu.org/licenses/>.
*/

/**
 * Represents one node of a Binary Search Tree that holds a key and value pair.
 * Based on Dr. Shaffer's C++ code.
 * 
 * @author Andrew Whitaker (aawhitak@vt.edu)
 * 
 */
public class BinNode<Key, Elem> implements BinNodeADT<Key,Elem>
{
    /* This node's key */
    private Key k;
    /* This node's element */
    private Elem it;
    /* The node's left and right child */
    BinNodeADT<Key, Elem> leftChild;
    BinNodeADT<Key, Elem> rightChild;

    /**
     * Creates a new node, and sets the left and right children to null.
     */
    public BinNode()
    {
	leftChild = rightChild = null;
    }

    /**
     * Creates a new node with the specified parameters.
     * 
     * @param key
     *                The node's key
     * @param e
     *                The node's value
     * @param l
     *                The node's left child
     * @param r
     *                The node's right child
     */
    public BinNode(Key key, Elem e, BinNode<Key, Elem> l, BinNode<Key, Elem> r)
    {
	k = key;
	it = e;
	leftChild = l;
	rightChild = r;
    }

    /**
     * Convenience method to see if this node is a leaf.
     */
    public boolean isLeaf()
    {
	return (leftChild == null) && (rightChild == null);
    }

    /**
     * Returns this node's left child.
     */
    public BinNodeADT<Key, Elem> left()
    {
	return leftChild;
    }

    /**
     * Returns this node's right child.
     */
    public BinNodeADT<Key, Elem> right()
    {
	return rightChild;
    }

    /**
     * Setter for this node's left child.
     */
    public void setLeft(BinNodeADT<Key,Elem> l)
    {
	leftChild = l;
    }

    /**
     * Setter for this node's right child.
     */
    public void setRight(BinNodeADT<Key, Elem> r)
    {
	rightChild = r;
    }

    /**
     * Sets the value of this node.
     */
    public void setVal(Elem val)
    {
	it = val;
    }

    /**
     * Returns this elements value.
     */
    public Elem val()
    {
	return it;
    }

    /**
     * @return This node's key
     */
    public Key key()
    {
	return k;
    }

}