Cod sursa(job #445381)

Utilizator auRSTARHreapca Aurelian auRSTAR Data 23 aprilie 2010 17:40:43
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.29 kb
Raporteaza aceasta sursa 
#include <stdio.h>
char a[2000010];
int i,j,N,nr;

int main()
{
	freopen("ciur.in","r",stdin);
	freopen("ciur.out","w",stdout);
	scanf("%i",&N);
	a[1]=1;
	for(j=2;j<=N;j++) 
	{
		if(!a[j])
		{
			nr++;
			for(i=2*j;i<=N;i+=j)
				a[i]=1;
		}
	}
	printf("%i",nr);
	return 0;
}