count_change.fs

open System;
open System.Diagnostics;

[<EntryPoint>]
let main argv = 
    let rec cc amount coins =
        match (amount, coins) with
        | (0,_) -> 1
        | (_,[]) -> 0
        | (amount,_) when amount < 0 -> 0
        | _ -> cc amount coins.Tail + cc (amount-coins.Head) coins
            
    let stopWatch = Stopwatch.StartNew()
    let x = cc 100 [1;2;3;4;5;6;7] 
    stopWatch.Stop();

    printfn "elapsed: %f"  stopWatch.Elapsed.TotalMilliseconds
    Console.ReadLine() |> ignore
    0