Splicing on a list only works in constant time if you happen to have a pointer near the part you want to delete. But in general, splicing on an array and on a linked list will take linear time - it's linear on the array because of all the movement of the elements that's needed, and it's linear on a linked list because you first need to get to the part that needs to be deleted. The deletion itself takes time linear to size of the part that needs to be deleted - unless you also have to happen a pointer at the end of the part that needs to be deleted.

Abigail