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