Implement the following functions using higher-order functions (and other predefined functions) of Haskell without using recursion.

- Implement a function
*flatten :: [[Int]] -> [Int]*that flattens a list of lists of integers in a list of integers. - Implement a function
*myLength :: String -> Int*that returns the length of a string. - Implement a function
*myReverse :: [Int] -> [Int]*that reverses a list of integers. - Implement a function
*countIn :: [[Int]] -> Int -> [Int]*that, given a list of sublists ℓ and an element*x*, returns the list that tells who many times*x*appears in each sublist of ℓ. - Implement a function
*firstWord :: String -> String*that, given a string with blanks and alphabetic characters, returns its first word.

**Scoring**

Each function scores 20 points.

Public test cases

**Input**

flatten [[1,2,3],[4,5],[6],[],[3,3]] myLength "Albert" myReverse [1..10] countIn [[3,2,3],[3],[], [2,2]] 3 firstWord " Volem pa amb oli "

**Output**

[1,2,3,4,5,6,3,3] 6 [10,9,8,7,6,5,4,3,2,1] [2,1,0,0] "Volem"

Information

- Author
- Albert Rubio / Jordi Petit
- Language
- English
- Translator
- Jordi Petit
- Original language
- Catalan
- Other languages
- Catalan
- Official solutions
- Haskell
- User solutions
- Haskell