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Google's “Director of Engineering” Hiring Test

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1764 points fatihky | 1 comments | 13 Oct 16 15:15 UTC | HN request time: 0.001s | source
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jblow ◴[13 Oct 16 16:07 UTC] No.12701702[source]▶
#9 is especially stupid because it's so context-dependent. SSE4 gives you a popcount instruction, for example, which would be easily the fastest way to do this, if available.
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greyman ◴[13 Oct 16 17:56 UTC] No.12702679[source]▶
Yes, but without that instruction, the algorithm mentioned by recruiter is really the quickest way. I coded chess algorithm in the past and this was exactly the method top chess open-source engines used. But imho it is hard to figure that out without prior experience with this problem.
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1. gcp ◴[13 Oct 16 20:37 UTC] No.12703834[source]▶
I coded chess algorithm in the past and this was exactly the method top chess open-source engines used.

Your statement is rather vague in time, but for example Stockfish did certainly use the hardware intrinsic at some point. Some of the top closed source engines were using SWAR approaches mixed with loops (when the expected population is 0).

The answer is very dependent on the exact HW architecture and the cache pressure in the surrounding algorithms.