Showing posts with label Prime generation. Show all posts
Showing posts with label Prime generation. Show all posts

Sunday, December 25, 2011

Efficient Algo to generate Prime numbers

After doing some little research for a prime number generation in Project euler. Just come to the conclusion that the below algorithm is the Most efficient algo for generating prime numbers.

Considerations:
1.Except 2 and 3 , all primes can be represent in the form of 6n+1 or 6n-1. [This leads to the conclusion that all primes are odd and it is not divided by  3.
2.And if a number is not divided by all the numbers below sqrt(number) then its a prime.
So it leads to the following pseudo code..

// Generating prime after 2 and 3
1.Read n
2.Divide it by the all odd numbers(above 3) less than sqrt(n).


P.s: Its 3 times faster than the usual code.If you know an efficient code other than this . Do comment that algo.