In which cases is it preferable to use ArrayList, and in which cases - LinkedList?

ArrayList is preferable when:

• Access to elements by index (get, set) occurs frequently.
• There are no frequent insertions or deletions of elements from the middle of the list.
• High-speed iteration over the list is required.

LinkedList is preferable when:

• Insertions or deletions of elements from the middle or beginning/end of the list occur frequently.
• Access operations by index are not frequent.
• High-speed sequential iteration over the entire list is not necessary (if index access is not needed, an iterator can be used).

Main differences:

Operation	ArrayList	LinkedList
Access by index	O(1)	O(n)
Insertion/deletion at end	O(1) (average)	O(1)
Insertion/deletion in middle	O(n)	O(1)
Memory usage	Less per element	More per element