Introduction - If you have any usage issues, please Google them yourself
Merge sort is an O(n log n) comparison-based sorting algorithm.
1. If the list is of length 0 or 1, then it is already sorted. Otherwise:
2. Divide the unsorted list into two sublists of about half the size.
3. Sort each sublist recursively by re-applying merge sort.
4. Merge the two sublists back into one sorted list.