Interviewbit a very good website for practicing programming questions and system design questions. Questions are grouped by topics and subtopics which is really good for practicing certain types of questions and eventually building up knowledge about all areas -- getting good at data structure and algorithms. So I am sharing the solution I did for all the programming practice questions and hopefully they can help you in understanding the questions.

--root
  --topics
    --individual question description, brief idea and solution

All solutions are in Python cause Python is concise and it is rich in data structure. And for interview purpose I highly recommend languages like Python/Ruby/JavaScript because you can save a lot of type declaration and you have rich data structures already. Go/Scala are good as well because of the fact that they do not need much type declaration upfront.