Google Software Engineer - Internship interview questions

Three Phone Interviews taken over a period of 2 months. The first two interviews took place back to back. First one was okay and focused on changing variable names from camel case to snake case and vice versa. The second involved removing a node and restructuring an ordered binary tree and went much better than the first one. Because I got fairly positive feedback, the third one was used to gauge whether I should go to hiring committee and was a graph search problem. It did not go well.

the process took about 1-2 month and was also over the Christmas break which might be why it was so long. i had 2 coding exercises for round one then had 2, 45 min interviews and heard back a few weeks later.