Daniel-Nikpayuk_SICP-Solutions/Chapter 1/1.2/exercise-1.12/exercise.lsp
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;; Copyright 2015 Daniel Nikpayuk
;;
;; This file is part of SICP Solutions.
;;
;; SICP Solutions is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License
;; as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
;;
;; SICP Solutions is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
;; of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License along with SICP Solutions. If not, see
;; <http://www.gnu.org/licenses/>.
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;pascal's triangle.

(define (pascal-row n)
 (define (succ r)
  (define (succ-cdr d)
   (if (or (null? d) (null? (cdr d))) d; optimization: otherwise return '()
    (cons
     (+ (car d) (car (cdr d)))
     (succ-cdr (cdr d))
    )
   )
  )
  (cons 1 (succ-cdr r))
 )
 (define (pastry r n)
  (if (= n 0) r
   (pastry (succ r) (- n 1))
  )
 )
 (pastry (list 1) n)
)

