namespace Algorithms.Sort

module PancakeSort =

let show data =

data |> Array.iter (printf "%d ")

printfn ""

let split (data: int []) pos = data.[0..pos], data.[(pos + 1)..]

let flip items pos =

let lower, upper = split items pos

Array.append (Array.rev lower) upper

let sort items =

let rec loop data limit =

if limit <= 0 then

data

else

let lower, upper = split data limit

let indexOfMax =

lower |> Array.findIndex ((=) (Array.max lower))

let partialSort =

Array.append (flip lower indexOfMax |> Array.rev) upper

loop partialSort (limit - 1)

loop items ((Array.length items) - 1)