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comp / comp.lang.lisp / McNuggets problem

Subject: McNuggets problem
From: B. Pym
Newsgroups: comp.lang.lisp
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Date: Mon, 5 Aug 2024 22:54 UTC

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From: Nobody447095@here-nor-there.org (B. Pym)
Newsgroups: comp.lang.lisp
Subject: McNuggets problem
Date: Mon, 5 Aug 2024 22:54:59 -0000 (UTC)
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rosettacode.org/wiki/McNuggets_problem

Calculate (from 0 up to a limit of 100) the largest
non-McNuggets number (a number n which cannot be expressed
with 6x + 9y + 20z = n where x, y and z are natural numbers).

Output:

newLISP

(define (cartesian-product lists)
(if (null? lists)
'(())
(let (subproduct (cartesian-product (rest lists)))
(apply append
(map
(fn (x) (map (fn (xs) (cons x xs)) subproduct))
(first lists))))))

(define (nug? x)
(let (top 100)
(exists
(fn (combo) (= x (apply + combo)))
(cartesian-product
(list (sequence 0 top 6)
(sequence 0 top 9)
(sequence 0 top 20))))))

(exists (fn (n) (not (nug? n))) (sequence 100 0))
===>
43

Subject	Author
McNuggets problem	B. Pym