This question was asked during an onsite C++ coding interview. I did NOT provide a good answer during that interview. So I was hoping to get feedback and suggestions from folks here at stack overflow. Now that I've had some more time to come up with a solution, I believe that I wrote a decent solution. I think this works OK as along as vin and car.equals() refer to different integers. If registration.equals() and a refer to the same integer, then that integer would be be clobbered to 0.
b答案 0 :(得分：6)
I think the intended trick here is
Form1.select()
Note that this uses 3 XOR's, like your solution, but only one masking operation. Plus, this is way friendlier on the CPU registers. There are no false dependency chains. And finally, it works if SELECT number, [A],[B],[C]
FROM (select category, number, numberincategory from a) t
PIVOT
(
SUM([numberincategory])
FOR category IN ([A],[B],[C])
) AS pvt;
.