defmodule SelectionSort do
  def sort(list), do: sort(list, [])
  def sort([], result), do: result
  def sort(list, result) do
    min = minimum(list)
    xs = delete(list, min)
    sort(xs, result ++ [min])
  end

  def minimum([head|tail]), do: minimum(tail, head)
  def minimum([], memo), do: memo
  def minimum([head|tail], memo) do
    minimum tail, (if head < memo, do: head, else: memo)
  end

  def delete(list, item), do: delete(list, item, [], true)
  def delete([], _, rest, _), do: rest
  def delete([head|tail], item, rest, flag) do
    if flag && (head == item) do
      delete(tail, item, rest, false)
    else
      delete(tail, item, rest ++ [head], flag)
    end
  end
end