12 lines
275 B
Racket
12 lines
275 B
Racket
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#lang racket
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(define (forward-difference list)
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(for/list ([x (cdr list)] [y list]) (- x y)))
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(define (nth-forward-difference n list)
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(for/fold ([list list]) ([n n]) (forward-difference list)))
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(nth-forward-difference 9 '(90 47 58 29 22 32 55 5 55 73))
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;; -> '(-2921)
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