(write-line "Hello World") ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; precednece finding ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; (defun entry (tree) (car tree))

(write-line "Hello World")
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; 
 ;; precednece finding
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; 
 (defun entry (tree) 
 (car tree)) 
 
 
 ;; Define left branch 
 (defun left-branch (tree) 
 (cadr tree)) 
 
 
 ;; Define right branch 
 (defun right-branch (tree) 
 (caddr tree)) 
 
 
 ;; Create node in a binary tree 
 (defun make-tree (entry left right) 
 (list entry left righta)) 
 
 
 ;; Insert element into tree 
 add (x tree) 
 (cond ((null tree) (make-tree x nil nil)) 
 ((= x (entry tree)) tree) 
 ((< x (entry tree)) (make-tree (entry tree) (add x 
 (left-branch tree)) (right-branch tree))) 
 ((> x (entry tree)) (make-tree (entry tree) 
 (left-branch tree) (add x (right-branch tree)))))) 
 
 
 ;; Create a binary tree function 
 (defun create-tree(elmnts) 
 (dolist (x elmnts) 
 (setf tree (add x tree))) 
 ) 
 
 
 ;; Create a null tree 
(setf tree nil) 
 
 NIL 
 
 
 ;; Add elements 
 (setf lst (list 23 12 1 4 5 28 4 9 10 45 89)) 
 
 
 (23 12 1 4 5 28 4 9 10 45 89) 
 
 
 (create-tree lst) 
 NIL 
 
 
 ;; Display the tree 
 tree 
 
 
(23 (12 (1 NIL (4 NIL (5 NIL (9 NIL (10 NIL NIL))))) NIL) (28 NIL (45 NIL (89 NIL NIL)))) 
 
 
 ;; Define inorder traveral  
 (defun inorder (tree) 
 (cond ((null tree)) 
 (t (inorder (left-branch tree)) 
 (print (entry tree)) 
(inorder (right-branch tree)))))) 
 
 ;;Define preorder traversal 
 (defun preorder (tree) 
 (cond ((null tree)) 
(t (print (entry tree)) 
 (preorder (left-branch tree)) 
 (preorder (right-branch tree)))))) 
 
 
 ;;Define postorder traversal 
 (defun postorder (tree) 
 (cond ((null tree)) 
 (t (postorder (left-branch tree)) 
(postorder (right-branch tree)) 
 (print (entry tree)))))