[thaumasiotes]

> But it is helpful to keep the terminology clear, because an insert in the middle of a linked list is still O(1), but inserting into the middle of an array will require moving some fraction of the data.

This is true if you already have a reference to the middle of the list. If you don't (say, because you want to insert while preserving the fact that the list is sorted), then inserting into a linked list is O(n) just like the array is.

[wolf550e]

Memory reads and memory writes are not the same. Linked list insert in the middle needs to do only O(1) writes. But because linked lists preclude memory prefetch, they should not be used these days.