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Ingy döt Net 2013-04-10 23:57:08 -07:00
parent 47bf37c096
commit b83f433714
12433 changed files with 156208 additions and 123 deletions
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Task/Pascals-triangle/Racket/pascals-triangle.rkt Normal file
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#lang racket
(define (pascal n)
(define (next-row current-row)
(map + (cons 0 current-row)
(append current-row '(0))))
(let-values
([(previous-rows final-row)
(for/fold ([triangle null]
[row '(1)])
([row-number (in-range 1 n)])
(values (cons row triangle)
(next-row row)))])
(reverse (cons final-row previous-rows))))