Question

What is the worst case complexity of accessing an element in ArrayList?

(a) O(n)

(b) O(1)

(c) O(nlogn)

(d) O(2)

This question was posed to me in a job interview.

This interesting question is from Data Structures-List in section java.util – The Collections Framework of Java

Answer 1

Right option is (b) O(1)

To explain I would say: ArrayList has O(1) complexity for accessing an element in ArrayList. O(n) is the complexity for accessing an element from LinkedList.