diff options
| -rw-r--r-- | one/fourteen.scm | 54 |
1 files changed, 34 insertions, 20 deletions
diff --git a/one/fourteen.scm b/one/fourteen.scm index 47156c7..4186238 100644 --- a/one/fourteen.scm +++ b/one/fourteen.scm @@ -2,28 +2,42 @@ ;;;; International. See ;;;; <https://creativecommons.org/licenses/by-sa/4.0/>. -;;; source from section 1.2.2 +;;; adapted from section 1.2.2 +;;; intolerable scheme drivel; ignore it. (define-module (one fourteen) - #:export (count-change - cc - first-denomination)) + #:export (get-cc + cc-range + cc-diff-list)) -(define (count-change amount) - (cc amount 5)) +(define (get-cc) + (let ((no-of-steps 0)) + (define (cc amount kinds-of-coins) + (set! no-of-steps (1+ no-of-steps)) + (cond ((= amount 0) 1) + ((or (< amount 0) (= kinds-of-coins 0)) 0) + (else (+ (cc amount + (- kinds-of-coins 1)) + (cc (- amount + (first-denomination kinds-of-coins)) + kinds-of-coins))))) + (define (first-denomination kinds-of-coins) + (cond ((= kinds-of-coins 1) 1) + ((= kinds-of-coins 2) 5) + ((= kinds-of-coins 3) 10) + ((= kinds-of-coins 4) 25) + ((= kinds-of-coins 5) 50))) + (lambda (amount) + (cc amount 5) + no-of-steps))) -(define (cc amount kinds-of-coins) - (cond ((= amount 0) 1) - ((or (< amount 0) (= kinds-of-coins 0)) 0) - (else (+ (cc amount - (- kinds-of-coins 1)) - (cc (- amount - (first-denomination kinds-of-coins)) - kinds-of-coins))))) +(define (cc-range amount limit incr) + (cond ((> amount limit) '()) + ((<= amount limit) + (cons ((get-cc) amount) + (cc-range (+ amount incr) limit incr))))) -(define (first-denomination kinds-of-coins) - (cond ((= kinds-of-coins 1) 1) - ((= kinds-of-coins 2) 5) - ((= kinds-of-coins 3) 10) - ((= kinds-of-coins 4) 25) - ((= kinds-of-coins 5) 50))) +(define (cc-diff-list l) + (cond ((= (length l) 1) '()) + ((> (length l) 1) (cons (+ (* -1 (car l)) (cadr l)) + (cc-diff-list (cdr l)))))) |