Mergesort
If we implement the mergesort using linked lists,
we do not need to be concerned with the amount
of time needed to move data
Instead, we just need to concentrate on the number of
comparisons.
When lists get very long, the  number of comparisons is
far less with the mergesort than it is with the insertion
sort.
Problems requiring 1/2 hour of computer time using the
insertion sort will probably require no more than a
minute using the mergesort.