The interview process is very straightforward: a phone screen with HR, a technical interview over the phone, and then an on-site interview.

Unfortunately, the interviewers are sometimes incredibly incompetent.

For the technical interview, I had this guy who not only called me 10 minutes late but also seemed to be in a ridiculous hurry to get the interview over with. On top of his hard-to-understand accent, the man was a complete train wreck at interviewing and did not understand basic things that I would explain to him. He also did not understand the C++ STL at all and thought that maps in C++ do not initialize objects, even though I decided to work around his misconception and assume that objects in maps are not initialized.

When I got the interview feedback back (through someone working at Google, because heaven forbid interviewees want some feedback on their interview – sick one, by the way, Google), the incompetent interviewer thought that I didn't understand the C++ STL, even though I was correct!

On top of that, he commented that one of my solutions for one of my problems was wrong and then said that a valid solution would be X, where X is literally the exact same solution I gave to him, just in code form.

Needless to say, I absolutely do not trust the Google interview process and would not recommend applying to a company that houses such arrogant and incompetent interviewers who have no idea what they're talking about.

Count the number of trigrams in a sentence.

Make a function that has a chance to select a particular trigram dependent upon its frequency in a sentence. (So if 'abc' appears 2 times and 'dog' appears once, then 'abc' should be selected 2/3 of the time).