Problem Statement

Take a string and repeat it some number of times.
Example: repeat("ha", 5)   =>   "hahahahaha" If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").

Let's start with the solution:

(apply str (repeat 5 "ha"))