import util.

go =>
  println(1..4=non_cont(1..4)),
  L = "abcde".reverse(),
  println(L=non_cont(L)),
  println(ernit=non_cont("ernit")),
  println(aaa=non_cont("aaa")),
  println(aeiou=non_cont("aeiou")),
  nl,

  println("Printing just the lengths for 1..N for N = 1..20:"),
  foreach(N in 1..20)
    println(1..N=non_cont(1..N).length) % just the length
  end,
  nl.

% get all the non-continuous subsequences
non_cont(L) = [ [L[I] : I in S] : S in non_cont_ixs(L.length)].

% get all the index positions that are non-continuous
non_cont_ixs(N) = [ P:  P in power_set(1..N), length(P) > 1, P.last() - P.first() != P.length-1].