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// Exercise 2.2 – Function Declaration I
// Define a function addNum1 that adds 1 to a number

open System

let addNum1(x:int)=
    printfn "%i" (x+1)

addNum1(10)

Console.ReadKey() |> ignore



// Define a function addNum10, which takes an integer argument, adds 10 to it, and returns the result.

open System

let addNum10(x:int):int=
    x+10

printfn "%i" (addNum10(10))

Console.ReadKey() |> ignore




// Define a function addNum20, which uses addNum10 to add 20 to a given integer


open System

let addNum10(x : int) : int =
    x + 10

let addNum20(y : int) : int =
    (addNum10(addNum10(y)))

printfn "%i" (addNum20(10))


Console.ReadKey() |> ignore


// Exercise 2.3 – Function Declaration II
// Define the function max2 that takes two integers as arguments and returns the largest of them

open System

let max2(x : int, y : int) : int =
    if x>y then x
    else y


printfn "%i" (max2(50, 10))

Console.ReadKey() |> ignore



// Define a function evenOrOdd that takes an integer and prints out “even number”
// if the given integer is even otherwise it prints out “odd number”.

open System

let evenOrOdd(x : int) =
    if (x % 2)= 0 then printfn "even number"
    else printfn "odd number"


evenOrOdd(51)

Console.ReadKey() |> ignore


// Define a function addXY that takes two integers and prints out the two integers before adding them.


open System

let addXY(x : int, y : int)=
    printfn "The sum of %i and %i is %i" x y (x+y)

addXY(50, 10)


Console.ReadKey() |> ignore

// (Exercise 2.4 Optional)
// Define a function addNum_j k that takes two integers j, k as arguments and
// returns j + 10*k. For instance, addNum_jk 3 5 = 3 + 10*5 = 53. You are,
// however, not allowed to use addition and multiplication directly: instead, you
// must write a recursive solution that calls addNum10 defined in Exercise 02.03
// above. (So addNum_jk 3 5 should be computed as 3 + 10 + 10 + 10 + 10 + 10.)


open System

let addNum10(x:int):int=
    x+10

let rec addNum_jk(j : int, k : int)=
    let m = addNum10(j)
    if( k = 1) then m
    else (addNum_jk(m,k-1))

printfn "%i" (addNum_jk(3, 5))

Console.ReadKey() |> ignore