1 ! Copyright (c) 2008 Aaron Schaefer.
2 ! See https://factorcode.org/license.txt for BSD license.
3 USING: kernel math.functions ranges project-euler.common
7 ! https://projecteuler.net/problem=56
12 ! A googol (10^100) is a massive number: one followed by
13 ! one-hundred zeros; 100^100 is almost unimaginably large: one
14 ! followed by two-hundred zeros. Despite their size, the sum of
15 ! the digits in each number is only 1.
17 ! Considering natural numbers of the form, a^b, where a, b <
18 ! 100, what is the maximum digital sum?
24 ! Through analysis, you only need to check when a and b > 90
26 : euler056 ( -- answer )
27 90 100 [a..b) dup cartesian-product concat
28 [ first2 ^ number>digits sum ] [ max ] map-reduce ;
30 ! [ euler056 ] 100 ave-time
31 ! 22 ms ave run time - 2.13 SD (100 trials)