Modern C - Challenge 1: Sequential sorting algorithms

Can you do:

• A merge sort (with recursion)
• A quick sort (with recursion)

on arrays with sort keys such as double or strings to your liking?

Nothing is gained if you don’t know whether your programs are correct. Therefore, can you provide a simple test routine that checks whether the resulting array really is sorted? This test routine should just scan once through the array and should be much, much faster than your sorting algorithms.