2013-10-27 22:24:23 +00:00
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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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2015-02-20 00:35:01 -05:00
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(labels ((fib (n a b)
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2013-10-27 22:24:23 +00:00
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(if (= n 0)
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a
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2015-02-20 00:35:01 -05:00
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(fib (- n 1) b (+ a b)))))
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(fib number 0 1))))
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