;; /home/comp212/Labs/lab4/sum.ss
;; By Dan Grossman, 96.Sep.30
;;
;; Some examples showing innacuracies using floating-point numbers,
;; and how to try to get around them.
;;
(define make-list
     (lambda (n s)
       (if (zero? n)
	   null
	   (cons s (make-list (sub1 n) s)))))

(define a (make-list 101 5))

; b: 1.0e16 followed by 101 5's
; c: 101 5's followed by 1.0e16
; d: 50 5's followed by 1.0e16 followed by 51 5's
; e: 1.0e16 followed by 50 5's
(define b (cons 1.0e16 a))
(define c (append a (cons 1.0e16 null)))
(define d (append (make-list 50 5) (cons 1.0e16 (make-list 51 5))))
(define e (cons 1.0e16 (make-list 50 5)))

(define sum
  (lambda (l)
    (cond ((null? l) 0)
	  (else (+ (car l) (sum (cdr l)))))))

(define bsum (sum b))
(define csum (sum c))
(define dsum (sum d))
(define esum (sum e))

(define Best-Sum
  (lambda (alon)
    (sum (Sort alon))))

(define Sort
  (lambda (alon)
    (cond ((null? alon) null)
	  (else (Insert (car alon) (Sort (cdr alon)))))))

;(define Insert
;  (lambda (n aslon)
;; ** HERE'S YOUR JOB! **
;    ))

; uncomment after you write Insert
;(define bsum2 (Best-sum b))
;(define csum2 (Best-sum c))
;(define dsum2 (Best-sum d))
;(define esum2 (Best-sum e))
;
;; What is the difference between bsum and bsum2?