L5

module FizzBuzz =
    let matchFizzBuzz i =
        match (i, i%3=0, i%5=0) with
        | (i, true, true) -> sprintf "%A FizzBuzz" i
        | (i, true, false) -> sprintf "%A Fizz" i
        | (i, false, true) -> sprintf "%A Buzz" i
        | (i, false, false) -> sprintf "%A" i

    let fizzBuzz =
        List.iter(fun i -> printfn "%A" (matchFizzBuzz i)) [1..20]

module Bisects =
    let isBisect year =
        match year with
        | year when year % 400 = 0 -> Some(year)
        | year when year % 100 = 0 -> None
        | year when year % 4 = 0 -> Some(year)
        | _ -> None

    let chooseLeapYears =
            [ 1900; 2000; 2016; 2017 ]
            |> List.choose isBisect
            |> List.iter (printfn "%d")

module Timey =
    let duration list =
        match list with
        | [] -> 0
        | [ s ] -> s
        | [ m; s ] -> m * 60 + s
        | h :: m :: s :: _ -> h * 3600 + m * 60 + s

module Shapes =
    open System
    type Shape =
        | Rectangle of height : float * width : float
        | Circle of radius : float

    let area shape =
        match shape with
        | Rectangle(h, w) -> h*w
        | Circle(r) -> Math.PI * r * r

    let rec readValidFloat () =
        let input = Console.ReadLine()
        let ok, num = Double.TryParse input

        match ok, num with
        | true, num when num > 0.0 -> num
        | _, _ -> readValidFloat()

    let rec validChoice() =
        printf "Shape type: "
        let shapeType = Console.ReadLine()
        match shapeType with
        | "C" | "c" -> 'C'
        | "D" | "d" -> 'D'
        | _ -> validChoice()

    let inputRectangle() =
        printfn "Introduceti lungimea:"

        let h = readValidFloat()
        printfn "Introduceti latimea:"
        let w = readValidFloat()
        Rectangle(h,w)

    let inputCircle() =
        printfn "Introduceti raza:"
        Circle(readValidFloat())

    let inputShape() =
        printfn "Introduceti D pentru dreptunghi si C pentru cerc: "
        if validChoice() = 'D' then inputRectangle()
        else inputCircle()

[<EntryPoint>]
let main argv =
    FizzBuzz.fizzBuzz
    Bisects.chooseLeapYears
    printfn "--------------------------------------"
    printfn "%d" (Timey.duration [23; 9; 5; 1; 4])
    printfn "%d" (Timey.duration [])
    printfn "%d" (Timey.duration [3])
    printfn "%d" (Timey.duration [2; 30])

    let s = Shapes.inputShape()
    printfn "Aria figurii '%A' este: %.2f" s (Shapes.area s)


    0 // return an integer exit code