(import std.Range :range :forEach)
(import std.List)

(mut doors (list:fill 100 false))
(let r (range 0 100))

(forEach r
  (fun (i) {
    (mut j i)
    (while (< j 100) {
      (@= doors j (not (@ doors j)))
      (set j (+ j i 1)) })
    (print doors) }))

(print
  (list:map
    (list:filter
      (list:zipWithIndex doors)
      (fun (e)
        (@ e 1)))
    (fun (e) (@ e 0))))