import util.

go =>
  Strings = ["broood", "bananaaa", "hiphophiphop"],
  foreach(String in Strings)
    check(String)
  end,
  nl.

% adjustments to 1-based index
encode(String) = [Pos,Table] =>
  Table = "abcdefghijklmnopqrstuvwxyz",
  Pos = [],
  Len = String.length,
  foreach({C,I} in zip(String,1..Len))
    Pos := Pos ++ [find_first_of(Table,C)-1],
    if Len > I then
       Table := [C] ++ delete(Table,C)
    end
  end.

decode(Pos) = String =>
  Table = "abcdefghijklmnopqrstuvwxyz",
  String = [],
  foreach(P in Pos)
    C = Table[P+1],
    Table := [C] ++ delete(Table,C),
    String := String ++ [C]
  end.

% Check the result
check(String) =>
   [Pos,Table] = encode(String),
   String2 = decode(Pos),
   if length(String) < 100 then
      println(pos=Pos),
      println(table=Table),
      println(string2=String2)
   else
      printf("String is too long to print (%d chars)\n", length(String))
   end,
   println(cond(String != String2, "not ", "") ++ "same"),
   nl.