BT_in_java.java

/// For hacktober

/* Class containing left and right child of current
node and key value*/
class Node
{
	int key;
	Node left, right;

	public Node(int item)
	{
		key = item;
		left = right = null;
	}
}

// A Java program to introduce Binary Tree
class BinaryTree
{
	// Root of Binary Tree
	Node root;

	// Constructors
	BinaryTree(int key)
	{
		root = new Node(key);
	}

	BinaryTree()
	{
		root = null;
	}

	public static void main(String[] args)
	{
		BinaryTree tree = new BinaryTree();

		/*create root*/
		tree.root = new Node(1);

		/* following is the tree after above statement

			1
			/ \
		null null	 */

		tree.root.left = new Node(2);
		tree.root.right = new Node(3);

		/* 2 and 3 become left and right children of 1
			1
			/	 \
		2	 3
		/ \	 / \
	null null null null */


		tree.root.left.left = new Node(4);
		/* 4 becomes left child of 2
					1
				/	 \
			2		 3
			/ \	 / \
			4 null null null
		/ \
		null null
		*/
	}
}