Background : Finished my four year degree from a top ranked University (B.S. Computer Science) in May 2019. I failed my interviews at Amazon and Facebook previously to discovering leetcode. I ended up working for a start up for 6 months after college before interviewing at Google HQ.

Preperation: I found out about leetcode in October of 2019 and solved problems throughout all of October, November, and December. I focused primarily on HashMaps, Trees, backtracking, dynamic programming, BFS, DFS, and string problems. I also read Cracking the Coding Interview and would solve problems from time to time on a whiteboard (ordered from amazon). I found practicing on a whiteboard really useful for the on site because it's much more difficult than coding in an editor (especially with intellisense). I watched YouTube videos from CS Dojo, Guarav Sen, Nick White, Kevin Naughton, HackerRank, and Tuschar Roy .

Interview: I was asked to solve two different Tree Problems during the interview and a string problem. Unfortunately I am unable to give exact questions due to NDA. The interview went pretty well, but not perfectly. Fortunately I ended up receiving an offer.

I'm not entirely sure this is the case for everyone, but tree problems seemed important during my interview process so if you plan on interviewing at Google I would suggest practicing Trees heavily.

LeetCode helped a lot in this process and I appreciate the filters that are in place for these problems. It made my studies much easier. I suggest LeetCode creates a YouTube channel because these questions are sometimes difficult to understand and explanation videos are quite helpful. Or maybe consider adding video solutions as a premium feature?