Write a recursive function named stutter_list that accepts a list of integers as a parameter and replaces every value in the list with two occurrences of that value.
For example, suppose a list named s stores these values, from bottom => top:
[13, 27, 1, -4, 0, 9]
Then the call of stutter_list(s) should change the list to store the following values:
[13, 13, 27, 27, 1, 1, -4, -4, 0, 0, 9, 9]
Notice that you must preserve the original order.
In the original list the 9 was at the top and would have been popped first.
In the new list the two 9s would be the first values popped from the list.
If the original list is empty, the result should be empty as well.
Constraints:
Your solution must be recursive.
Do not use any loops.
Do not use any auxiliary collections or data structures to solve this problem.
