# Quicksort with lomuto partition - how many repeating elements are too many?

I know that quicksort with Lomuto's partition method faces worst case run-time $$\Theta(n^2)$$ when there are many repeating elements in the array.

However, I'm trying to figure out - how many repeating elements are too many?

For example, what if the given array has exactly $$n/2$$ repeating elements?