Why does the reverse function for the std::list class in the C++ standard library have linear runtime? I would think that for doubly-linked lists the reverse function should have been O(1). Reversing a doubly-linked list should just involve switching the head and the tail pointers. 7 Answers 7
I understand that Tortoise and Hare’s meeting concludes the existence of a loop, but how does moving tortoise to the beginning of linked list while keeping the hare at the meeting place, followed by moving both one step at a time make them meet at the starting point of the cycle? 23 Answers 23
Why would someone want to use a linked-list over an array? Coding a linked-list is, no doubt, a bit more work than using an array and one may wonder what would justify the additional effort. I think insertion of new elements is trivial in a linked-list but it’s a major chore in an array. Are … Read more
I am trying to to understand why Java’s ArrayDeque is better than Java’s LinkedList as they both implement Deque interface. I hardly see someone using ArrayDeque in their code. If someone sheds more light into how ArrayDeque is implemented, it would be helpful. If I understand it, I will be more confident using it. I … Read more
I use a lot of lists and arrays but I have yet to come across a scenario in which the array list couldn’t be used just as easily as, if not easier than, the linked list. I was hoping someone could give me some examples of when the linked list is notably better. 15 Answers … Read more
Is it a linked list, an array? I searched around and only found people guessing. My C knowledge isn’t good enough to look at the source code. 9 Answers 9
When is it better to use a List vs a LinkedList? 15 Answers 15
Say you have a linked list structure in Java. It’s made up of Nodes: class Node { Node next; // some user data } and each Node points to the next node, except for the last Node, which has null for next. Say there is a possibility that the list can contain a loop – … Read more
I’ve always been one to simply use: List<String> names = new ArrayList<>(); I use the interface as the type name for portability, so that when I ask questions such as this, I can rework my code. When should LinkedList be used over ArrayList and vice-versa? 3 33
Summary ArrayList with ArrayDeque are preferable in many more use-cases than LinkedList. If you’re not sure — just start with ArrayList. TLDR, in ArrayList accessing an element takes constant time [O(1)] and adding an element takes O(n) time [worst case]. In LinkedList adding an element takes O(n) time and accessing also takes O(n) time but LinkedList … Read more
