//zad 1
let PoleObw (a:float) (h:float) =
    let Pole a h = a*h/2.0
    let Obw a = a*3.0
    (Pole a h, Obw a)


let PszOsz (a:float) =
    let Psz a = (a * a * sqrt 3.0) / 4.0
    let Osz a = a*6.0
    (Psz a, Osz a)

printfn "%A" (PoleObw 2.0 4.0)
printfn "%A" (PszOsz 2.0 )


//zad2
let rec dod (x:int) (n:int) =
    if n <= 1 then x
    else x + (dod x (n-1))

printfn "%A" (dod 2 3)


//zad 3
let rec mno (x:int) (n:int) =
    if n <= 1 then x
    else x * (mno x (n-1))

printfn "%A" (mno 2 3)

//zad4
let rec CoDrugi list ak =
    match list with
    | [] -> []
    | x::xs -> if ak % 2 = 0 then x::CoDrugi xs (ak+1) else CoDrugi xs (ak+1)
printfn "%A" (CoDrugi [ 1 ; 2 ; 3 ; 4] 0)

//zad5
let CoDrugi2 list =
    list |> List.mapi(fun i el -> el , i)
          |> List.filter(fun (el,i) -> i % 2=0)
          |> List.map fst

printfn "%A" (CoDrugi2 [1;2;3;4;5;8;8])

//zad6
let rec ListaPodzN list ak n =
    match list with
    | [] -> []
    | x::xs -> if x % n = 0 then x::ListaPodzN xs (ak+1) n else ListaPodzN xs (ak+1) n
printfn "%A" (ListaPodzN [ 1 ; 2 ; 3 ; 4] 0 3)

//zad7
let Filtr list n = List.filter(fun x -> x%n=0) list
printfn "%A" (Filtr [2;3;5;4;6] 2)


//zad8
type ksiazka = {
    tytul : string
    autor : string
    rok : int
    wydawnictwo : string
    strony : int
    oprawa : bool
    }

//zad9


let mxmi list =
   let rec min list m =
        match list with
        | [] -> m
        | x::xs -> if x < m then min xs x else min xs m
   let rec max list m =
       match list with
       | [] -> m
       | x::xs -> if x > m then max xs x else max xs m
   (min list (List.head list) , max list (List.head list))

printfn "%A" (mxmi [1;2;4;5;8;7;9;5;45])

//zad10
let maxmin list =
    (List.min(list),List.max(list))
printfn "%A" (maxmin [1;2;3;4;5;6;8])


//zad11

let lista =[1;2;3;4;5;6;7;8];

let srednia list =
   let rec suma list =
       match list with
       | [] ->  0
       | x::xs -> x + (suma xs)
   let rec ilosc list ak =
       match list with
       | [] -> ak
       | x::xs -> ilosc xs (ak+1)
   printf "srednia: %A" (suma list / ilosc list 0)

srednia lista

//zad12
let srednia2 list =
    let foldd list =
        List.fold (+) 0 list
    printfn "srednia z fold %A"  (foldd list / list.Length)
srednia2 lista

//zad13
(*let lista =[1;2;3;4;5;6;7;8];
let wieksze list k o=
    let rec rek1 list k o=
        match list with
           | [] -> o
           | x::xs -> if(x<k) then rek1 xs k (o+1) else rek1 xs k o
    rek1 list k o

printf "%A" (wieksze lista 4 0);

let wiekszeW list k=
   let filtr list k =
        List.filter (fun x -> x<k) list
   (filtr list k).Length

printf "%A" (wiekszeW lista 4);

*)