1996-11-27 15:52:01 -04:00
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#! /usr/bin/env python
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1994-08-19 12:09:02 -03:00
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# Print digits of pi forever.
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#
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# The algorithm, using Python's 'long' integers ("bignums"), works
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# with continued fractions, and was conceived by Lambert Meertens.
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#
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# See also the ABC Programmer's Handbook, by Geurts, Meertens & Pemberton,
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# published by Prentice-Hall (UK) Ltd., 1990.
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import sys
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from mpz import mpz
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def main():
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mpzone, mpztwo, mpzten = mpz(1), mpz(2), mpz(10)
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k, a, b, a1, b1 = mpz(2), mpz(4), mpz(1), mpz(12), mpz(4)
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while 1:
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# Next approximation
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p, q, k = k*k, mpztwo*k+mpzone, k+mpzone
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a, b, a1, b1 = a1, b1, p*a+q*a1, p*b+q*b1
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# Print common digits
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d, d1 = a/b, a1/b1
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while d == d1:
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output(d)
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a, a1 = mpzten*(a%b), mpzten*(a1%b1)
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d, d1 = a/b, a1/b1
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def output(d):
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# Use write() to avoid spaces between the digits
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# Use int(d) to avoid a trailing L after each digit
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sys.stdout.write(`int(d)`)
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# Flush so the output is seen immediately
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sys.stdout.flush()
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main()
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