100 doors

editable example

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ghul

use IO.Std.write_line

use Ghul.Pipes

let doors = (1::100) |> map(_ => false) |> collect_list()

for pass in 1::100 do

let door mut = pass

while door <= 100 do

doors[door - 1] = !doors[door - 1]

door = door + pass

od

od

let open_doors = (1::100) |> filter(door => doors[door - 1])

write_line("open doors: {$open_doors}")

open doors: [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]