I'm not too sure about this line....
if (n > Math.Sqrt(n))
return true;
On 12 Nov, 10:22, ram <[EMAIL PROTECTED]> wrote:
> With the below configuration i got 7746653 primes founds in 10
> seconds Highest Prime is :15493305
>
> CPU: Intel Pentiun E2140@ Dual 1.60GHZ
> RAM: 2GB
> OS: Windows 2003 Server
> .Net: 2.0
>
> I used different logic. because suppose to decide a number whether
> it is prime number or not, we no need to check all the numbers below
> the square root of that number. IF we check all the primes of below
> the square root of that number, its enough. because except 1 , atleast
> 1 factor of non-primary number must be a primary number. using this
> principle, we can find quicker than checking all numbers under the
> sqrt of the number.
>
> List<int> primes = new List<int>();
> protected void Page_Load(object sender, EventArgs e)
> {
> int seconds = 10;
> primes.Add(2);
> primes.Add(3);
> primes[1] = 3;
> DateTime x, y = DateTime.Now;
> int a = 4, b = 2;
> do
> {
> if (IsPrim(a))
> {
> primes.Add(a);
> b++;
> }
> a++;
> x = DateTime.Now;
> } while ((x - y).TotalSeconds < seconds);
> Response.Write(b.ToString() + " primes founds in " +
> seconds+ " seconds");
> Response.Write("Highest Prime is :" + primes[primes.Count -
> 1].ToString());
> }
>
> private bool IsPrim(int Num)
> {
> foreach(int n in primes)
> {
> if (Num % n == 0)
> return false;
> if (n > Math.Sqrt(n))
> return true;
> }
> return true;
> }
>
> On Nov 11, 2:10 pm, CK <[EMAIL PROTECTED]> wrote:
>
> > This is something I've been working on for a while, and I thought it
> > might be fun to push it out to the group to see if anyone can better
> > my efforts.
>
> > The challange is to write a Windows Console App that generates prime
> > numbers. It does not need to generate them in any specific order,
> > record them, or even catch all primes. The aim is to calculate as
> > many unique primes as possible in 10 seconds.
>
> > Obviously, this will depend on the processor it runs on, so that will
> > be taken into account.
>
> > Once you have a solution, please post your results like the following:
> > (this is example data only)
>
> > CPU: Intel E6300
> > Cores: 2
> > RAM: 1GB
> > OS: Vista Home Premium
> > .Net: 3.5
> > Number of primes in 10 seconds: 10,000
> > Highest Prime found: 123247
>
> > To confirm your code is working properly, please post some large
> > primes (~100000) your code has found to verify that it is working
> > correctly.
>
> > Please also be willing to share your code.
>
> > Please enter, just for fun, and enjoy :)
>
> > PS. A Prime is a number that is only divisible by itself and 1. 1 is
> > not a prime, 2 is, 3 is, 4 isn't, 5 is etc.
