Subj : Re: Faster algorithm for prim numbers..!!
To   : comp.programming
From : Michael Jørgensen
Date : Thu Sep 22 2005 07:51 am


"Robert Bralic" <robo_bralic@yahoo.co.uk> wrote in message
news:dgr19m$52g$1@ss405.t-com.hr...
> I weated a simple program, he is compiled
> with gcc, and generates prim numbers,
> with fastes method that I find.He is based
> on divide with generated prim numbers...
> At end he gives time report on format:
> dd:hh:mi:sec...
> Precompile as gcc prim.c -o prim, and use
> him as "prim upper_bound",as example:
> "prim 1000".If anybody have some idea
> how to make algorithm fastes write to me...!!

Well, inside the loop "for(i=1;i<k;i++)" you call malloc(). This function is
very slow.

Use "gprof" to determine where the program uses time.

-Michael.

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