SUPREMEWARRIOR'S PROFILE

import javax.swing.JOptionPane;

public class Tree{
	Node root = null;
	
	// Sets Node a as the root node, if the tree is empty. 
	// Otherwise returns an error
	public Node addRoot(String element, Node n){
		if(root == null){
			Node r = new Node(element, n);
			root = r;
		} else {
			JOptionPane.showMessageDialog(null, this, "Error, root node is already present", 0);
		}
		return getRoot();
	}
	
	// Returns the root node
	public Node getRoot(){
		return root;
	}
	
	// Removes Node d from the tree, if Node d has any children in the left
	// or right branch of the subtree, replace the child node with Node d and
	// return Node d
	// Return an error if Node d has two child nodes.
	public void removeNode(Node n){
		if(n.getRight()==null&&n.getLeft()==null){
			n = null;
		} else if(n.getRight()!=null){
			n = n.getRight();
		} else if(n.getLeft()!=null){
			n = n.getLeft();
		} else if(n.getRight()!=null&&n.getLeft()!=null){
			JOptionPane.showMessageDialog(null, this, "Error, cannot remove a node that has two child nodes", 0);
		}
	}
	
	// Checks for a left node, if there isn't makes Node b the new left node with element
	// as the value of the Node b. If there is a left node return an error
	public Node insertLeft(Node n, String element){
		// If there is no left node, make Node b the left node
		if(n == null){
			n.leftNode = new Node(element, n);
		// If there is already a left node, return an error 
		} else {
			JOptionPane.showMessageDialog(null, this, "Error, left node is already present", 0);
		}
		return n.leftNode;
	}
	
	// Checks for a right node, if there isn't makes Node c the new right node with element
	// as the value of the Node c. If there is a right node return an error
	public Node insertRight(Node n, String element){
		// If there is no right node, make Node c the right node
		if(n == null){
			n.rightNode = new Node(element, n);
		// If there is already a right node, return an error 
		} else {
			JOptionPane.showMessageDialog(null, this, "Error, right node is already present", 0);
		}
		return n.rightNode;
	}

	// Attaches subtree
	public void attach(){}
	
	public class Node {
		String element;
		Node nextNode;
		Node leftNode, rightNode = null;
		
		// Creates a node with the given element and next node
		public Node(String s, Node n){
			element = s;
			nextNode = n;
		}
		
		// Sets the right node
		public void setRight(Node n){
			rightNode = n;
		}
		
		// Returns the right node
		public Node getRight(){
			return rightNode;
		}

		// Sets the left node
		public void setLeft(Node n){
			leftNode = n;
		}
		
		// Returns the left node
		public Node getLeft(){
			return leftNode;
		}

		// Sets the next node of this node
		public void setNext(Node n){
			nextNode = n;
		}
		
		// Returns the next node of this node
		public Node getNext(){
			return nextNode;
		}
		
		// Sets the element of this node
		public void setElement(String newElement){
			element = newElement;
		}
		
		// Returns the element of the node
		public String getElement(){
			return element;
		}
	}
}

import javax.swing.JOptionPane;

public class Tree{
	Node root = null;
	Node leftNode = null;
	Node rightNode = null;
	
	// Returns the root node
	public Node getRoot(){
		return root;
	}
	
	// Sets the root node, if the tree is empty. 
	// Otherwise adds node to the tree
	public Node addRoot(String element, Node a){
		if(root == null){
			Node r = new Node(element, a);
			root = r;
		} else {
			JOptionPane.showMessageDialog(null, this, "Error, root node is already present", 0);
		}
		return getRoot();
	}
	
	// Checks if there is a left node, if there isn't makes Node b the new left node with element
	// as the value of the Node b. If there is a left node return an error
	public Node insertLeft(Node b, String element){
		// If there is no left node, make Node b the left node
		if(b == null){
			leftNode = new Node(element, b);
		// If there is already a left node, return an error 
		} else {
			JOptionPane.showMessageDialog(null, this, "Error, left node is already present", 0);
		}
		return leftNode;
	}
	
	// Checks if there is a right node, if there isn't makes Node c the new right node with element
	// as the value of the Node c. If there is a right node return an error
	public Node insertRight(Node c, String element){
		// If there is no right node, make Node c the right node
		if(c == null){
			rightNode = new Node(element, c);
		// If there is already a right node, return an error 
		} else {
			JOptionPane.showMessageDialog(null, this, "Error, right node is already present", 0);
		}
		return rightNode;
	}
	
	// Removes Node d from the tree, if Node d has any children in the left
	// or right branch of the subtree, replace the child node with Node d and
	// return Node d
	// Return an error if Node d has two child nodes.
	public void removeNode(Node d){
		if(d.getRight()==null&&d.getLeft()==null){
			d = null;
		} else if(d.getRight()!=null){
			d = d.getRight();
		} else if(d.getLeft()!=null){
			d = d.getLeft();
		} else if(d.getRight()!=null&&d.getLeft()!=null){
			JOptionPane.showMessageDialog(null, this, "Error, cannot remove a node that has two child nodes", 0);
		}
	}

	// Attaches subtree
	public void attach(){
		
	}
	
	public class Node {
		String element;
		Node nextNode;
		Node head, tail;
		int size;
		
		// Creates a node with the given element and next node
		public Node(String s, Node n){
			element = s;
			nextNode = n;
		}
		
		// Returns the right node
		public Node getRight(){
			return rightNode;
		}
		
		// Returns the left node
		public Node getLeft(){
			return leftNode;
		}
		
		// Returns the element of the node
		public String getElement(){
			return element;
		}
		
		// Returns the next node of this node
		public Node getNext(){
			return nextNode;
		}
		
		// Sets the element of this node
		public void setElement(String newElement){
			element = newElement;
		}
		
		// Sets the next node of this node
		public void setNext(Node newNext){
			nextNode = newNext;
		}
		
		// Adds the node to the last node of the list
		public void addFirst(Node first){
			first.setNext(head);		// Points to the previous head node
			head = first;				// Make the head node point to the new node
			size = size + 1;			// Increment the node count
		}
		
		// Adds the node to the last node of the list
		public void addLast(Node last){
			last.setNext(null);			// Make the new node "last" point to null
			tail.setNext(last);			// Make the old tail node point to the new tail node
			tail = last;				// Make tail node point to new node
			size = size + 1;			// Increment the node count			
		}
		
		// Removes the first node in the list. Before removing it points to the 
		// new head node then removes the old head node.
		public void removeFirst(Node v){
			if(head == null){
				System.out.println("Error, cannot remove. The list is empty");
			}
			v = head;
			head = head.getNext();
			v.setNext(null);
			size = size - 1;
		}
	}
}
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