> It definitely doesn't take 500 leetcode problems.
I'd say it depends on many things. What level are you applying to. And also, how well you perform in situation of stress. And of course, in the end, it's a competition. If the other applicant can solve problems faster than you, they'll get the job and you won't.
For me the hard part wasn't solving the problem, but solving them in 15 minutes. At Google, 2/3 problems I got were hard and not medium. There would be no chance that I solved any of them if I hadn't seen them before.
Interesting, was that in the EU? I recently had a friend go through the process in the bay area, he didn't get anything harder than easy/medium. I thought that Google, at least, was trending to making their algo portion easier as they introduced design questions instead. 2/3 hard questions is pretty crazy and anyone would struggle with that unless they grind a lot like you suggest. Might be you just got really unlucky with the interviewer or there is a culture in that office of asking hard algo questions.
I'd say it depends on many things. What level are you applying to. And also, how well you perform in situation of stress. And of course, in the end, it's a competition. If the other applicant can solve problems faster than you, they'll get the job and you won't.
For me the hard part wasn't solving the problem, but solving them in 15 minutes. At Google, 2/3 problems I got were hard and not medium. There would be no chance that I solved any of them if I hadn't seen them before.