! -----------
! A printing shop runs 16 batches (jobs) every week and each batch requires a
-! sheet of special colour-proofing paper of size A5.
+! sheet of special color-proofing paper of size A5.
! Every Monday morning, the foreman opens a new envelope, containing a large
! sheet of the special paper with size A1.
: (pick-sheet) ( seq i -- newseq )
[
- <=> sgn
+ <=>
{
- { -1 [ ] }
- { 0 [ 1- ] }
- { 1 [ 1+ ] }
+ { +lt+ [ ] }
+ { +eq+ [ 1 - ] }
+ { +gt+ [ 1 + ] }
} case
] curry map-index ;
: (euler151) ( x -- y )
table get [ {
{ { 0 0 0 1 } [ 0 ] }
- { { 0 0 1 0 } [ { 0 0 0 1 } (euler151) 1+ ] }
- { { 0 1 0 0 } [ { 0 0 1 1 } (euler151) 1+ ] }
- { { 1 0 0 0 } [ { 0 1 1 1 } (euler151) 1+ ] }
- [ [ dup length [ pick-sheet ] with map sum ] [ sum ] bi / ]
+ { { 0 0 1 0 } [ { 0 0 0 1 } (euler151) 1 + ] }
+ { { 0 1 0 0 } [ { 0 0 1 1 } (euler151) 1 + ] }
+ { { 1 0 0 0 } [ { 0 1 1 1 } (euler151) 1 + ] }
+ [ [ dup length <iota> [ pick-sheet ] with map-sum ] [ sum ] bi / ]
} case ] cache ;
: euler151 ( -- answer )
{ 1 1 1 1 } (euler151)
] with-scope ;
-! TODO: doesn't work currently, problem in area of 'with map' in (euler151)
-
! [ euler151 ] 100 ave-time
! ? ms run time - 100 trials