White board interviews 'should' be about how you think on your feet and whether you can explain your process. 'But' they seldom are. Frequently, the interviewers are technical people and they are expecting a specific set of solutions - ones they have seen before for a given problem.
It is possible to practice, even memorize, specific algorithms. There are books out there that are set up in a nice format to do so. I have read through and worked with many algorithms, but refuse to memorize them. Because I LIKE thinking through a problem and devising new strategies.
I often fail whiteboards! And I'm okay with that. The few times I've turned the interview around (because I wasn't totally whipped) have been when I started speaking to what I do know, to what I can do, and why. It is unfortunate that many interviews are about regurgitation.
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