Add solutions mimipaskova for week1.

week1/1-Beginner-Tasks/first.hs

@@ -0,0 +1,152 @@
+add x y  = x + y
+
+-- 01. Even
+evenn :: Integer -> Bool
+evenn number = if number `mod` 2 == 0 then True else False
+
+-- 02. Odd
+oddn :: Integer -> Bool
+oddn number = if number `mod` 2 /= 0 then True else False
+
+-- 03. Calculate BMI
+bmi :: Double -> Double -> Double
+bmi height weight = weight / ((height / 100) ^ 2)
+
+-- 04. Convert degrees to radians
+deg2Rad, rad2Deg :: Double -> Double
+deg2Rad degree = (degree /180 ) * pi
+
+-- 05. Convert radians to degrees
+rad2Deg radians = (radians / pi) * 180
+
+-- 06. Does it form a triangle?
+isTriangle, isTriangle1 :: Int -> Int -> Int ->  Bool
+isTriangle  a b c = if (a + b > c) && (a + c > b) && (b + c > a) && a > 0 && b > 0 && c > 0 then True else False
+
+isTriangle1  a b c = (a + b > c) && (a + c > b) && (b + c > a) && a > 0 && b > 0 && c > 0 
+
+-- 07. Perimeter of a triangle
+perimeter :: Double -> Double -> Double -> Double
+perimeter a b c = a + b + c
+
+-- 08. Area of a triangle
+area :: Double -> Double -> Double -> Double
+area a b c = sqrt(((perimeter a b c ) / 2) * ((perimeter a b c)/2 - a) * ((perimeter a b c)/2 - b) * ((perimeter a b c)/2 - c))
+
+-- 09. Calculate
+calculate :: Char -> Integer -> Integer -> Integer
+calculate sign x y = if sign == '+'
+					then x + y else
+					if sign == '-'
+					then x - y else
+					if sign == '*'
+					then x * y else
+					error "Unknown operator!"
+
+-- 10. Currency Converter (working with dollars, levs and euros)
+convert :: String -> String -> Double -> Double
+convert str1 str2 money
+	| str1 == "bgn" && str2 == "usd" = money / 1.737
+	| str1 == "usd" && str2 == "bgn" = money * 1.737
+	| str1 == "bgn" && str2 == "eur" = money / 1.959
+	| str1 == "eur" && str2 == "bgn" = money * 1.959
+	| str1 == "eur" && str2 == "usd" = money * 1.116
+	| str1 == "usd" && str2 == "eur" = money / 1.116
+
+-- 13. Head
+headd, lastt :: [a] -> a
+headd (h:t) = h
+headd [] = error "list is empty"
+
+-- 14. Tail
+taill :: [a] -> [a]
+taill (h:t) = t
+taill [] = error "List is empty"
+
+-- 16. Last
+lastt (h:[]) = h
+lastt (h:t) = lastt t
+lastt [] = error "Empty list"
+
+-- 17. Double all elements
+-- double :: [a] -> [b]
+double [] = []
+double (h:t) = h * 2 : double(t)
+
+-- TO ASK for recursion
+-- 18. More generic - make it possible to multiply all elements in a list with a given number
+mult number [] = []
+mult number (h:t) = (h * number) : mult number t
+
+-- To ask for signature
+-- 19. Get the n-th element of a list
+-- nth :: a-> [b] -> b
+nth 1 (h:t) = h
+nth number (h:t) = nth (number-1) t
+
+-- 20. Is an element member of a list?
+-- member :: a -> [a] -> Bool
+member number [] = False
+member number (h:t) = if h == number
+						then True
+						else member number t
+
+-- 21. Is the list a fibonacci sequence?
+-- isFibonacciSequence :: [a] -> Bool
+isFibonacciSequence (h:(h2:(h3:[]))) = if h + h2 /= h3
+										then False
+										else True
+isFibonacciSequence (h:(h2:(h3:t))) = if h + h2 /= h3
+										then False
+										else isFibonacciSequence (h2:(h3:t))
+
+-- 22. Get the sum of a list
+summ, productt :: [Int] -> Int
+summ (h:[]) = h
+summ (h:t) = h + summ t
+
+-- 23. Get the product of a list
+productt (h:[]) = h
+productt (h:t) = h * productt t
+
+-- 24. Multiply lists
+multLists :: [Int] -> [Int] -> [Int]
+multLists [] [] = []
+multLists arr [] = []
+multLists [] arr = []
+multLists (h1:t1) (h2:t2) = h1 * h2 : multLists t1 t2
+
+-- isValidID id = (id.lenght == 10) && sum(id)%11 = 0
+
+-- 30  Concatenate the lists
+concatenate :: [a] -> [a] -> [a]
+concatenate [] second = second
+concatenate first [] = first
+concatenate (h:t) second = h : concatenate t second
+
+-- 31Take all elements of a list without the last one
+initt [] = error "You can't do that with the empty list!"
+initt (h:[]) = []
+initt (h:t) = h : initt t
+
+-- 32 Take the first n elements from a list
+takee, dropp :: Int -> [a] -> [a]
+takee _ [] = []
+takee 0 _ = []
+takee number (h:t) = h : takee (number-1) t
+
+-- 33. Drop the first n elements from a list
+dropp _ [] = []
+dropp 0 arr = arr
+dropp number (h:t) = dropp (number - 1) t
+
+-- 34. Zipping lists
+zipp :: [a] -> [b] -> [(a, b)]
+zipp [] [] = []
+zipp arr [] = []
+zipp [] arr = []
+zipp (h1:t1) (h2:t2) = (h1, h2) : zipp t1 t2
+
+
+-- unzipp :: [(a,b)] -> ([c])
+-- unzipp