Lab1_PF

import Data.List

myInt = 5555555555555555555555555555555555555555555555555555555555555555555555555555555555555

double :: Integer -> Integer
double x = x+x


--maxim :: Integer -> Integer -> Integer
maxim x y = if (x > y)
               then x
          else y

max3 x y z = let
             u = maxim x y
             in (maxim  u z)

triple :: Integer -> Integer
triple x = x + x + x

max4 x y z t = let
             u = maxim x y
             v = maxim z t
             in (maxim u v)

patrat x y = x * x + y * y


paritate :: Integer -> String
paritate x = if ( x `mod` 2 == 0)
                    then "par"
          else "impar"

factorial x = if (x == 0 || x == 1)
          then 1
          else x * factorial(x-1)

factorial' 0 = 1
factorial' 1 = 1
factorial' n = n * factorial'(n-1)

factorial2 n
     |n == 0 = 1
     |n == 1 = 1
     |n < 0 = error "nr negativ"
     |otherwise = n * factorial2(n-1)

verificare x y = if( x > y + y)
          then True
          else False