33 lines
890 B
Factor
33 lines
890 B
Factor
! Copyright (c) 2008 Aaron Schaefer.
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! See http://factorcode.org/license.txt for BSD license.
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USING: kernel math.combinatorics project-euler.common
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sequences ;
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IN: project-euler.024
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! http://projecteuler.net/index.php?section=problems&id=24
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! DESCRIPTION
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! -----------
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! A permutation is an ordered arrangement of objects. For example, 3124 is one
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! possible permutation of the digits 1, 2, 3 and 4. If all of the permutations
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! are listed numerically or alphabetically, we call it lexicographic order. The
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! lexicographic permutations of 0, 1 and 2 are:
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! 012 021 102 120 201 210
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! What is the millionth lexicographic permutation of the digits 0, 1, 2, 3, 4,
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! 5, 6, 7, 8 and 9?
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! SOLUTION
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! --------
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: euler024 ( -- answer )
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999999 10 <iota> permutation digits>number ;
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! [ euler024 ] 100 ave-time
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! 0 ms ave run time - 0.27 SD (100 trials)
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SOLUTION: euler024
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