How to sort in-place using the merge sort algorithm?

Question

I know the question is not too specific.

All I want is someone to tell me how to convert a normal merge sort into an in-place merge sort (or a merge sort with const

Answer 1

Just for reference, here is a nice implementation of a stable in-place merge sort. Complicated, but not too bad.

I ended up implementing both a stable in-place merge sort and a stable in-place quicksort in Java. Please note the complexity is O(n (log n)^2)