1 ! Copyright (c) 2008 Aaron Schaefer.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: kernel math.combinatorics project-euler.common
7 ! http://projecteuler.net/index.php?section=problems&id=24
12 ! A permutation is an ordered arrangement of objects. For example, 3124 is one
13 ! possible permutation of the digits 1, 2, 3 and 4. If all of the permutations
14 ! are listed numerically or alphabetically, we call it lexicographic order. The
15 ! lexicographic permutations of 0, 1 and 2 are:
17 ! 012 021 102 120 201 210
19 ! What is the millionth lexicographic permutation of the digits 0, 1, 2, 3, 4,
26 : euler024 ( -- answer )
27 999999 10 <iota> permutation digits>number ;
29 ! [ euler024 ] 100 ave-time
30 ! 0 ms ave run time - 0.27 SD (100 trials)