Answer Happy

Write a python function called find_duplicates(s) which takes a
string, s, that may have repeated characters in it, and returns a
list of all repeated characters in the string. If you created a
string, list, dictionary, and/or set inside your function, what
data structure(s) did you create and why? What is the time
complexity of your solution and why?
Function
Parameters
A string that may contains repeated characters.
Return Value
A list of characters that have duplicates in the input string.
The characters in the list can be in any order.
Example