6 lines
179 B
Common Lisp
6 lines
179 B
Common Lisp
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(defun choose (n k)
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(labels ((prod-enum (s e)
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(do ((i s (1+ i)) (r 1 (* i r))) ((> i e) r)))
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(fact (n) (prod-enum 1 n)))
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(/ (prod-enum (- (1+ n) k) n) (fact k))))
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