Harmonize spelling

[factor.git] / extra / project-euler / 116 / 116.factor

diff --git a/extra/project-euler/116/116.factor b/extra/project-euler/116/116.factor
index d48cdf175c48c761ddf5576a36e21146746a4fc1..229c62ec7456b3365000acfa0bf0b6e449f94eaf 100644 (file)
--- a/extra/project-euler/116/116.factor
+++ b/extra/project-euler/116/116.factor
@@ -1,7 +1,6 @@
-! Copyright (c) 2008 Eric Mertens
+! Copyright (c) 2008 Eric Mertens.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: kernel math math.ranges sequences sequences.lib ;
-
+USING: kernel math ranges sequences project-euler.common ;
 IN: project-euler.116
 
 ! http://projecteuler.net/index.php?section=problems&id=116
@@ -10,20 +9,21 @@ IN: project-euler.116
 ! -----------
 
 ! A row of five black square tiles is to have a number of its tiles replaced
-! with coloured oblong tiles chosen from red (length two), green (length
+! with colored oblong tiles chosen from red (length two), green (length
 ! three), or blue (length four).
 
 ! If red tiles are chosen there are exactly seven ways this can be done.
 ! If green tiles are chosen there are three ways.
 ! And if blue tiles are chosen there are two ways.
 
-! Assuming that colours cannot be mixed there are 7 + 3 + 2 = 12 ways of
+! Assuming that colors cannot be mixed there are 7 + 3 + 2 = 12 ways of
 ! replacing the black tiles in a row measuring five units in length.
 
 ! How many different ways can the black tiles in a row measuring fifty units in
-! length be replaced if colours cannot be mixed and at least one coloured tile
+! length be replaced if colors cannot be mixed and at least one colored tile
 ! must be used?
 
+
 ! SOLUTION
 ! --------
 
@@ -38,18 +38,23 @@ IN: project-euler.116
 <PRIVATE
 
 : nth* ( n seq -- elt/0 )
-    [ length swap - 1- ] keep ?nth 0 or ;
+    [ length swap - 1 - ] keep ?nth 0 or ;
 
 : next ( colortile seq -- )
-     [ nth* ] [ peek + ] [ push ] tri ;
+     [ nth* ] [ last + ] [ push ] tri ;
 
 : ways ( length colortile -- permutations )
-    V{ 1 } clone [ [ next ] 2curry times ] keep peek 1- ;
-
-PRIVATE>
+    V{ 1 } clone [ [ next ] 2curry times ] keep last 1 - ;
 
 : (euler116) ( length -- permutations )
-    3 [1,b] [ ways ] with sigma ;
+    3 [1..b] [ ways ] with map-sum ;
 
-: euler116 ( -- permutations )
+PRIVATE>
+
+: euler116 ( -- answer )
     50 (euler116) ;
+
+! [ euler116 ] 100 ave-time
+! 0 ms ave run time - 0.34 SD (100 trials)
+
+SOLUTION: euler116