Driver code
public static void main ( String args [ ] ) { Node root = new Node ( 1 ) ; root . left = new Node ( 2 ) ; root . right = new Node ( 3 ) ; root . left . left = new Node ( 4 ) ; root . left . right = new Node ( 5 ) ; root . right . left = new Node ( 6 ) ; root . right . right = new Node ( 7 ) ; root . left . left . left = new Node ( 8 ) ; root . left . left . right = new Node ( 9 ) ; root . left . right . left = new Node ( 10 ) ; root . left . right . right = new Node ( 11 ) ; root . right . left . left = new Node ( 12 ) ; root . right . left . right = new Node ( 13 ) ; root . right . right . left = new Node ( 14 ) ; root . right . right . right = new Node ( 15 ) ; print2D ( root ) ; } }