1 ! Copyright (c) 2007 Aaron Schaefer.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: io io.files kernel math.parser namespaces project-euler.common sequences
4 splitting system vocabs ;
7 ! http://projecteuler.net/index.php?section=problems&id=67
12 ! By starting at the top of the triangle below and moving to adjacent numbers
13 ! on the row below, the maximum total from top to bottom is 23.
20 ! That is, 3 + 7 + 4 + 9 = 23.
22 ! Find the maximum total from top to bottom in triangle.txt (right click and
23 ! 'Save Link/Target As...'), a 15K text file containing a triangle with
26 ! NOTE: This is a much more difficult version of Problem 18. It is not possible
27 ! to try every route to solve this problem, as there are 2^99 altogether! If you
28 ! could check one trillion (10^12) routes every second it would take over twenty
29 ! billion years to check them all. There is an efficient algorithm to solve it. ;o)
37 : (source-067) ( -- path )
39 "project-euler.067" vocab-root ?resource-path %
41 "\\project-euler\\067\\triangle.txt" %
43 "/project-euler/067/triangle.txt" %
47 : source-067 ( -- triangle )
48 (source-067) <file-reader> lines [ " " split [ string>number ] map ] map ;
52 : euler067 ( -- answer )
55 ! [ euler067 ] 100 ave-time
56 ! 15 ms run / 0 ms GC ave time - 100 trials