Timeline for Prime numbers, Prime Factors and LCM
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
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| Nov 22, 2012 at 17:15 | vote | accept | Adil Mughal | ||
| Oct 19, 2012 at 7:12 | comment | added | Peter Taylor |
@GeneS, either pull the Sqrt out of the loop (and downcast to int) or invert the test to i * i < n (because processors have a single instruction for multiplication, but sqrt is expensive).
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| Oct 18, 2012 at 17:22 | comment | added | Gene S | @PeterTaylor So for my own education, what would be a better way of doing an early escape? | |
| Oct 18, 2012 at 16:25 | comment | added | Peter Taylor |
@GeneS, true, although that's the worst possible way of doing the early escape. I didn't focus too much on IsPrime because I knew I was going to point out that it's unnecessary.
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| Oct 18, 2012 at 16:20 | comment | added | Gene S | You could also skip a larger number of tests in the IsPrime function by using the Math.Sqrt(n) in the for statement ... for (int i = 2; i <= Math.Sqrt(n); i++) | |
| Oct 18, 2012 at 16:14 | comment | added | Adil Mughal | since it's just for self-learning and fun, that's why I also tried that. But what I meant with alternative was any better approach to do with prime factorization | |
| Oct 18, 2012 at 15:47 | comment | added | Peter Taylor | @AdilMughal, there's the obvious approach of not using prime factorisation, but you've explicitly chosen not to use gcd. | |
| Oct 18, 2012 at 13:33 | comment | added | Adil Mughal | +1. Thanks Peter. Is there alternative approach you can think of for LeastCommonMultipleByPrimeFactorization. | |
| Oct 18, 2012 at 12:48 | history | answered | Peter Taylor | CC BY-SA 3.0 |