Data commit

Task/Superpermutation-minimisation/Ruby/superpermutation-minimisation-1.rb

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+#A straight forward implementation of N. Johnston's algorithm. I prefer to look at this as 2n+1 where
+#the second n is first n reversed, and the 1 is always the second symbol. This algorithm will generate
+#just the left half of the result by setting l to [1,2] and looping from 3 to 6. For the purpose of
+#this task I am going to start from an empty array and generate the whole strings using just the
+#rules.
+#
+#Nigel Galloway: December 16th., 2014
+#
+l = []
+(1..6).each{|e|
+  a, i = [], e-2
+  (0..l.length-e+1).each{|g|
+     if not (n = l[g..g+e-2]).uniq!
+       a.concat(n[(a[0]? i : 0)..-1]).push(e).concat(n)
+       i = e-2
+     else
+       i -= 1
+     end
+   }
+   a.each{|n| print n}; puts "\n\n"
+   l = a
+}

Task/Superpermutation-minimisation/Ruby/superpermutation-minimisation-2.rb

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+def superperm(n)
+  return [1] if n==1
+  superperm(n-1).each_cons(n-1).with_object([]) do |sub, ary|
+    next if sub.uniq!
+    i = ary.empty? ? 0 : sub.index(ary.last)+1
+    ary.concat(sub[i..-1] + [n] + sub)
+  end
+end
+
+def to_16(a) a.map{|x| x.to_s(16)}.join end
+
+for n in 1..10
+  ary = superperm(n)
+  print "%3d: len =%8d :" % [n, ary.size]
+  puts n<5 ? ary.join : to_16(ary.first(20)) + "...." + to_16(ary.last(20))
+end