module _52

open System

let findSameDigits =
    // todo: optimize with combination of available digits
    let powerOfTenNums pow = 
        let b = Math.Pow(10.0, float pow) |> int
        seq {1..(b-1)} |> Seq.map ((+) b)
    let multiples num =
        seq {num*2..num..(num*6) }
    let numSet num =
        Set (common.numDigits num)
    let rec sd pow =
        powerOfTenNums pow
        |> Seq.filter ( fun n ->
            let nDigits = numSet n
            multiples n
            |> Seq.map (fun m -> numSet m)
            |> Seq.forall (fun mDigits -> nDigits = mDigits)
            )
        |> Seq.map (fun n -> (n, multiples n |> Seq.toArray))
        
    sd 5