Definetely. I arrived at the final stage in a Google interview which I failed and I can confirm that out of the 5 interviews three were based on puzzles that I

Definetely. I arrived at the final stage in a Google interview which I failed and I can confirm that out of the 5 interviews three were based on puzzles that I later discovered are found in books for coding competions. On two I did a good job to work out a solution myself but I completely got the third wrong. Who prepares for this kind of competitions has a huge advantage in these kind of interviews.