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.

-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.