7L7W - Haskell

day1.hs

module Main where
    
    -- Primer ejercicio
    
    vuelta [] = []
    vuelta (h:t) = vuelta t ++ [h]
    
    -- Segundo ejercicio
    
    combinations aList = [(a, b) | a <- aList, b <- aList, a < b]

    -- Tercer ejercicio
    
    multitable = [ (a, b, a * b) | a <- [1..12], b <- [1..12]]
    
    -- Cuarto ejercicio
    
    colors = ["red", "green", "blue"]
    coloring = [(alabama, mississippi, georgia, tennessee, florida) | alabama <- colors, mississippi <- colors, georgia <- colors, 
        tennessee <- colors, florida <- colors, alabama /= mississippi, tennessee /= mississippi, alabama /= tennessee, alabama /= mississippi,
        alabama /= georgia, alabama /= florida, georgia /= tennessee, georgia /= florida]

day2.hs

module Main where
    
    -- Primer ejercicio
    
    ordena [] = []
    ordena (h:t) = ordena (filter ( <= h) t) ++ [h] ++ ordena (filter ( > h) t)
    
    -- Segundo ejercicio
    
    ordenacustom [] comp = []
    ordenacustom (h:t) comp = ordenacustom (filter ((/= h) . head . comp h) t) comp ++ [h] ++ ordenacustom (filter ((== h) . head . comp h) t) comp
    
    -- Probar con ordenacustom [1,3,5,2,3,6] (\x y -> if (x < y) then [x, y] else [y, x])
    
    -- Tercer ejercicio
    
    multrange start multiplier = start:(multrange (start * multiplier) multiplier)
    
    digit2int char = fromEnum char - (fromEnum '0')
    isDigit char = char >= '0' && char <= '9'
    
    
    conv2number (str) = 
        fromIntegral (foldl (+) 0 
                            (zipWith (*) 
                                    (take (length str) (multrange 1 10)) 
                                    (map (digit2int) (reverse (filter (isDigit) str)))
                            )
                    ) / 100.0
                    
    
    -- Cuarto ejercicio
    
    everythird (x) 
        | length x > 2 = (last (take 3 x)):(everythird (drop 3 x))
        | otherwise = []
        
        
    everyfifth (x)
        | length x > 5 = (last (take 3 x)):(everythird (drop 3 x))
        | otherwise = []
        
    -- Quinto ejercicio    
    
    half = (/ 2) 
    
    append str1 str2 = str1 ++ str2
    toline = (flip append) "\n"