6.001 recitation 3/16/07tagsstacks and queuesDr. Kimberle Koile(car ‘ ‘list)tagsstacks and queues• constructor: (make-stack) • selectors: (top stack) (stack-elements stack)• operations: (stack? stack)(empty-stack? stack)(insert-stack-elt stack elt) (delete-stack-elt stack) stacks• constructor: (define (make-stack) • selectors: (define (top stack)• operations: (define (stack? stack)(define (empty-stack? stack)stacks(define (tagged-list? tag l) (and (pair? l) (eq? tag (car l))))(define *stack-tag* 'stack)1. Fill in the code for insert-stack-elt (aka push) for a stack.(define (insert-stack-elt element stack)(if (stack? stack)(cons(error "Insert on a non-stack")))stack problems(cons)2. Write delete-stack-elt (aka pop) for a stack. This version of pop should return a new stack that contains all elements except the top. (Don't forget the two error checks.)stack problems(define delete-stack-elt (stack))• constructor: (make-queue) • selectors: (front-queue queue) (queue-elements queue)• operations: (queue? queue)(empty-queue? queue)(insert-queue-elt queu elt) (delete-queue-elt queue) queues(define (tagged-list? tag l) (and (pair? l) (eq? tag (car l))))(define *queue-tag* 'queue)3. Write insert-queue-elt for a queue. (Don't forget an error check.)queue problems(define insert-queue-elt (queue))4. Write delete-queue-elt for a queue. (Don't forget an error check.)queue problems(define delete-queue-elt (queue))• constructor: (make-it) • selectors: (first-elt s-or-q) (elements s-or-q)• operations: (is-type? s-or-q)(empty? s-or-q)(insert-element s-or-q elt) (delete-element s-or-q) stacks and queues(define delete-elt s-or-q))5.Write a delete-elt procedure that works on either stacks or queues.stacks and queuesacdstacksX(delete! s)stacks and
View Full Document
Unlocking...