open System

exception UJEMNY_ARGUMENT;;

let razyDwa x = 2 * x;;

let past x=
   match x with
   | "run" -> "ran"
   | "do" -> "done"
   | "swim" -> "swam"
   | x -> x + "ed"
   | _ -> "blad"

let rec silnia x =
   match x with
   | 0 -> 1
   | _ -> x*(silnia (x - 1));;

let rec siln (n) =
   if (n = 0) then 1
   elif n > 0 then n * (siln (n-1))
   else raise UJEMNY_ARGUMENT;;

let parz n =
   if (n % 2) = 0 then true
   else false;;

let parz2 n = (n % 2) = 0;;

let ( ---> ) p q = (not p) || q;;

let czyItyCharWStringu (str:System.String) i ch = str.Chars(i) = ch;

let rec ( ^^ ) m n=
   if n=0 then 1
   else m * (m^^(n-1));;

let rec suma (m, n) =
    if (n = 0) then m
    else m + suma (m, n - 1) + n;;

let rec tylkoMale (st:System.String, i:int) =
    if i <> 0 then (
       if (Char.IsUpper(st.[0])) then false
       else tylkoMale(st, i - 1)
    )
    else true;;

let sprawdzString (st:System.String) = tylkoMale (st, st.Length - 1);;

let rec ( & ) m n =
   match n with
   | 0 -> 0
   | 1 -> m
   | _ -> m + m * (n-1);;

let mutable res = 0
let mutable str = ""

let rec wystOdItego (st:string, i:int, ch:char) =
   str <- st
   if (i > str.Length-1) then res
   else (
      str <- str.Substring(i,str.Length-i)
      printf "%A\n" str
      if str.[0] = ch then res <- res+1
      else res <- res
      wystOdItego(str, 1, ch)
   );;


[<EntryPoint>]
let main argv =
    let wynik = wystOdItego("dbcdadwdqqq",5,'d')
    printf "%A\n" wynik
    System.Console.ReadKey() |> ignore
    0 // zwracanie kodu zakończenia w postaci liczby całkowitej