9 lines
258 B
Common Lisp
9 lines
258 B
Common Lisp
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(defun fib (number)
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"Fibonacci sequence function."
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(if (< number 0)
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(error "Error. The number entered: ~A is negative" number)
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(recursive ((n number) (a 0) (b 1))
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(if (= n 0)
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a
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(recurse (- n 1) b (+ a b))))))
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