I still don't understand why I did not pass.

I had a phone interview where I was asked to write code and solve a puzzle, and I did both.

I was informed later by HR that I did not pass, and I was simply shocked. I asked what was wrong, but their policy is not to disclose anything.

I think Google has some serious issues with its interviewing process.

Sample uniformly on a circle centered at zero with radius 1.

Write code to check whether every element of an array has been visited. You are given a starting position, and each position stores a pointer to a subsequent position.