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11 May 2004 @ 07:46 pm
Argh!  
I had a phone interview with Surreal today. The last phone interview they had they asked several questions about camera space/world sapce and matrix multiplication, so i reviewed those this afternoon before the interview.So of course for this interview they asked me lots about dot product and cross product =P

I did better on those since i've worked with them more frequently, but a few of the questions i knew i'd solved before but couldn't remember how i solved them, and when he asked me what the definiton of the dot product was i totally blanked. I know what the dot product _does_ but normally i just use the dotproduct function in whatever codebase i'm using, so i'm not as familiar with the actual mathematical formula as i should be.

I wish i had a memory that worked for the stuff i wanted it to =P

Oh, btw, anyone have any good ideas for how to multiply a number by 14 without using multiply or divide? The best i could come up with was adding the number 7 times in a for loop and then bit shifting it to the left one.
 
 
Current Mood: annoyedannoyed
 
 
 
Kevinbellwethr on May 11th, 2004 10:46 pm (UTC)
Shift left 4x, subtract original value 2x? This method would use fewer operations.

DonAithnendonaithnen on May 12th, 2004 01:17 am (UTC)
Yeah, that would work a lot better, thanks. So i had the right idea with the bitshifts, but just didn't go far enough with it. Maybe i got partial credit, if such a thing exists in an interview :)