I received a call from a recruiter, and a month later, I went for an onsite interview. There were four interviews: two before lunch and two after. In each interview, my interviewer was looking for my approach and how I arrived at that approach, rather than just the solution.

It's true that you must complete the code by the end of each interview session to be considered. It doesn't matter which website you chose for practice questions; all that matters is how much you've practiced and how comfortable you are with a whiteboard.

Practice solid code for these algorithms:

• Breadth-First Search (BFS): You should be able to write solid code in 15 minutes or less on a whiteboard.
• Depth-First Search (DFS): You should be able to write solid code in 15 minutes or less on a whiteboard.
• Recursion: Understand its application with computed results for arrays of elements, trees, Binary Search Trees (BSTs), and checking for infinite loops.

Understand every data structure from stacks to graphs. You should be able to provide definitions and relevant formulas, such as formulas for complete binary trees, height, maximum level of a balanced binary tree, number of nodes, and number of leaves, along with their real-life applications.

The video "How to Work at Google - Candidate Coaching Session: Tech Interviewing" might give you a false impression that it's acceptable to be less than proficient in an interview, but it's not.

You should be able to:

1. Come up with an algorithm.
2. Finish writing solid code.
3. Know basic definitions of all data structures.
4. When writing code, know all basic libraries used (e.g., Math, IO, Convert).

Good luck!