15 lines
338 B
Scheme
15 lines
338 B
Scheme
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; Recursive function to return the Nth Stern-Brocot sequence number.
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(define stern-brocot
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(lambda (n)
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(cond
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((<= n 0)
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0)
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((<= n 2)
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1)
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((even? n)
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(stern-brocot (/ n 2)))
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(else
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(let ((earlier (/ (1+ n) 2)))
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(+ (stern-brocot earlier) (stern-brocot (1- earlier))))))))
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