Chapter 3 Daily 06

Write the type signature and function for each problem.

1. Add a 3 to the front of a list of numbers.

2. Add a 4 to the back of a list of numbers.

3. Add a 5 in the middle of a list of numbers. If possible, insert the 5 so there are exactly the same number of numbers before and after it, otherwise put the extra number after it.

4. Switch the front and back number in a list of numbers. Leave the others the same.

5. Delete the middle number of a list of numbers. Assume the length is odd.

6. delRange start end numList: Remove items from index start through index end from the numbers list.

    delRange 1 4 [10,11,12,13,14,15] == [10,15]
    delRange 3 7 "PlatypusFiesta" == "PlaFiesta"
   
    Work:
    PlatypusFiesta
    01234567Fiesta
   

7. (moveOdd) Move any odd numbers from the start of a list to the end. Stop moving when you find an even number. If there are no even numbers, the list does not change.

    moveOdd [1,3,4,5,6] == [4,5,6,1,3]
    moveOdd [2,3,5,7,9] == [2,3,5,7,9]
   

8. (vDub) Double all of the vowels in a word.

    vDub "Alligator" == "AAlliigaatoor"
   

Note

Using if statements for 7 and 8 is fine. Your code might feel more like “Racket code” for those… until we learn about guards.