32 lines
880 B
Factor
32 lines
880 B
Factor
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! Copyright (c) 2008 Aaron Schaefer.
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! See http://factorcode.org/license.txt for BSD license.
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USING: math math.functions ;
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IN: project-euler.097
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! http://projecteuler.net/index.php?section=problems&id=97
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! DESCRIPTION
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! -----------
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! The first known prime found to exceed one million digits was discovered in
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! 1999, and is a Mersenne prime of the form 2^6972593 − 1; it contains exactly
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! 2,098,960 digits. Subsequently other Mersenne primes, of the form 2p − 1,
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! have been found which contain more digits.
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! However, in 2004 there was found a massive non-Mersenne prime which contains
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! 2,357,207 digits: 28433 * 2^7830457 + 1.
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! Find the last ten digits of this prime number.
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! SOLUTION
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! --------
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: euler097 ( -- answer )
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2 7830457 10 10 ^ ^mod 28433 * 10 10 ^ mod 1+ ;
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! [ euler097 ] 100 ave-time
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! 0 ms run / 0 ms GC ave time - 100 trials
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MAIN: euler097
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