Data commit

Task/Hailstone-sequence/Oz/hailstone-sequence.oz

@@ -0,0 +1,24 @@
+declare
+  fun {HailstoneSeq N}
+     N > 0 = true %% assert
+     if N == 1 then         [1]
+     elseif {IsEven N} then N|{HailstoneSeq N div 2}
+     else                   N|{HailstoneSeq 3*N+1}
+     end
+  end
+
+  HSeq27 = {HailstoneSeq 27}
+  {Length HSeq27} = 112
+  {List.take HSeq27 4} = [27 82 41 124]
+  {List.drop HSeq27 108} = [8 4 2 1]
+
+  fun {MaxBy2nd A=A1#A2 B=B1#B2}
+     if B2 > A2 then B else A end
+  end
+
+  Pairs = {Map {List.number 1 99999 1}
+           fun {$ I} I#{Length {HailstoneSeq I}} end}
+
+  MaxI#MaxLen = {List.foldL Pairs MaxBy2nd 0#0}
+  {System.showInfo
+   "Maximum length "#MaxLen#" was found for hailstone("#MaxI#")"}