Add generic Node classes (#2782)

Co-authored-by: Andrii Siriak <siryaka@gmail.com>

DevUtils/Nodes/SimpleTreeNode.java

@@ -0,0 +1,81 @@
+package DevUtils.Nodes;
+
+/**
+ * Simple TreeNode extension that holds references
+ * to two child Nodes (left and right).
+ * 
+ * @param <E> The type of the data held in the Node.
+ * 
+ * @author <a href="https://github.com/aitorfi">aitorfi</a>
+ */
+public class SimpleTreeNode<E> extends TreeNode<E> {
+    /** Refrence to the child Node on the left. */
+    private SimpleTreeNode<E> leftNode;
+    /** Refrence to the child Node on the right. */
+    private SimpleTreeNode<E> rightNode;
+
+    /** Empty contructor. */
+    public SimpleTreeNode() {
+        super();
+    }
+
+    /**
+     * Initializes the Nodes' data.
+     * 
+     * @param data Value to which data will be initialized.
+     * @see TreeNode#TreeNode(Object)
+     */
+    public SimpleTreeNode(E data) {
+        super(data);
+    }
+
+    /**
+     * Initializes the Nodes' data and parent node reference.
+     * 
+     * @param data Value to which data will be initialized.
+     * @param parentNode Value to which the nodes' parent reference will be set.
+     * @see TreeNode#TreeNode(Object, Node)
+     */
+    public SimpleTreeNode(E data, SimpleTreeNode<E> parentNode) {
+        super(data, parentNode);
+    }
+
+    /**
+     * Initializes the Nodes' data and parent and child nodes references.
+     * 
+     * @param data Value to which data will be initialized.
+     * @param parentNode Value to which the nodes' parent reference will be set.
+     * @param leftNode Value to which the nodes' left child reference will be set.
+     * @param rightNode Value to which the nodes' right child reference will be set.
+     */
+    public SimpleTreeNode(E data, SimpleTreeNode<E> parentNode, SimpleTreeNode<E> leftNode, SimpleTreeNode<E> rightNode) {
+        super(data, parentNode);
+        this.leftNode = leftNode;
+        this.rightNode = rightNode;
+    }
+
+    /**
+     * @return True if the node is a leaf node, otherwise false.
+     * @see TreeNode#isLeafNode()
+     */
+    @Override
+    public boolean isLeafNode() {
+        return (leftNode == null && rightNode == null);
+    }
+
+    public SimpleTreeNode<E> getLeftNode() {
+        return leftNode;
+    }
+
+    public void setLeftNode(SimpleTreeNode<E> leftNode) {
+        this.leftNode = leftNode;
+    }
+
+    public SimpleTreeNode<E> getRightNode() {
+        return rightNode;
+    }
+
+    public void setRightNode(SimpleTreeNode<E> rightNode) {
+        this.rightNode = rightNode;
+    }
+}