[<EntryPoint>]
let main argv =

    let numbers = [ 1; 7; 7; 9; 9; 3 ]
    let series = [ (0, 1); (1, 2); (3, 2); (5, 1) ]

    let calculateSeries data =
        let rec traverseData data origin start count = seq {
            match data with
            | [] -> yield (start, count)
            | h::t ->
                if origin = h then
                    yield! traverseData t origin start (count + 1)
                else
                    yield (start, count)
                    yield! traverseData t h (start + count) 1
        }
        match data with
        | [] -> []
        | h::t -> traverseData data h 0 0 |> List.ofSeq

    let printIntervalInfo (start, count) = printfn "%d %d" start count

    printfn "etalon series"
    series |> List.iter printIntervalInfo

    printfn "computed series"
    numbers |> calculateSeries |> List.iter printIntervalInfo

    0