Do take a look at this also
http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes#cite_note-7
Source code to list all prime numbers till number n
#include<iostream>
#include<algorithm>
#define bool int
using namespace std;
int main(){
int n;
cin>>n;
int i,j;
bool primeValues[1000]={0};
for(i=4;i<=n;i=i+2){
primeValues[i] = 1;
}
for(i=3;i*i<=n;i=i+2){
for(j=2;j<n/i;j++)
primeValues[i*j] = 1;
}
for(i=2;i<n;i++){
if(primeValues[i] == 0)
cout<< i<<" ";
}
}
On Sun, Jul 24, 2011 at 11:51 AM, frank <abb...@gmail.com> wrote:
> thanq u very much
>
> On Jul 23, 10:13 pm, arun kumar <kumar0...@gmail.com> wrote:
> > hope this link will help youhttp://
> www.topcoder.com/tc?module=Static&d1=tutorials&d2=primalityTes...
> >
> >
> >
> >
> >
> >
> >
> > On Sat, Jul 23, 2011 at 10:39 PM, frank <abb...@gmail.com> wrote:
> > > what is the efficient algorith to find the prime numbers or to check a
> > > number prime or not ?
> > > Helpful if the pseudo code provided.
> >
> > >>>>thank you
> >
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