Amazon Software Development Engineer interview questions

Phone Interview#2: a) Check two binary trees are same. b) Design Java ArrayList

F2F: a) find the top k repeated string in the list of string b)Least common ancestor. c)Finding the max sum of 3 element subset in an array. 1 10 6 1 0 32 4 ==>36 d)Design a In memory Voting System to handle concurrent users access e) (Bar raiser)Multiple logs of server containing (time,sessionId,userId,Page) user can navigate page from 1 server to other server. find the three page subset sequence repeated maximum number of times hint:- pushing all file data to DB we can solve this f) Check weather string is a palindrome given a string as Interator<Character>

Describe an Array. What are the benefits/drawbacks?

How does a linked list work? What are the benefits/drawbacks?

Write a method to find the sum of all nodes with no siblings in a binary tree.