Amazon Software Engineer interview questions

== Java == 1. interface vs abstract class 2. the usages of 'final' keyword 3. overload vs override 4. concept of 'equals' and how to override (need to override hashCode() also) 5. checked vs unchecked exception == Misc == 1. 50,000 HTML pages, extract the ones with phone numbers (regex) 2. Find the odd-occurence number in an array (I told him that I have seen the problem before and he asked the next one) 3. Find the duplicate number in an array of N ints (1<=x<=N-1) 4. Design a transportation system (warehouses, routes, trucks, fuel, MPG, etc)

1st round was not too tough . general technical questions about networking , data structure. Second phone round was drilling