-
Notifications
You must be signed in to change notification settings - Fork 205
/
089.factor
49 lines (37 loc) · 1.37 KB
/
089.factor
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
! Copyright (c) 2009 Doug Coleman.
! See https://factorcode.org/license.txt for BSD license.
USING: io.encodings.ascii io.files kernel math
project-euler.common roman sequences ;
IN: project-euler.089
! https://projecteuler.net/problem=89
! DESCRIPTION
! -----------
! The rules for writing Roman numerals allow for many ways of
! writing each number (see FAQ: Roman Numerals). However, there
! is always a "best" way of writing a particular number.
! For example, the following represent all of the legitimate
! ways of writing the number sixteen:
! IIIIIIIIIIIIIIII
! VIIIIIIIIIII
! VVIIIIII
! XIIIIII
! VVVI
! XVI
! The last example being considered the most efficient, as it
! uses the least number of numerals.
! The 11K text file, roman.txt (right click and 'Save
! Link/Target As...'), contains one thousand numbers written in
! valid, but not necessarily minimal, Roman numerals; that is,
! they are arranged in descending units and obey the subtractive
! pair rule (see FAQ for the definitive rules for this problem).
! Find the number of characters saved by writing each of these
! in their minimal form.
! SOLUTION
! --------
: euler089 ( -- n )
"resource:extra/project-euler/089/roman.txt" ascii file-lines
[ ] [ [ roman> >roman ] map ] bi
[ [ length ] map-sum ] bi@ - ;
! [ euler089 ] 100 ave-time
! 14 ms ave run time - 0.27 SD (100 trials)
SOLUTION: euler089