Cod sursa(job #336508)

Utilizator prdianaProdan Diana prdiana Data 31 iulie 2009 17:33:55
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include <stdio.h>
#define max_n 2000000
bool a[max_n+2];

int main()
{
	freopen("ciur.in","r",stdin);
	freopen("ciur.out","w",stdout);

	int n,i,j,nrsol = 1;
	scanf("%d",&n);
	for (i=3;i<=n;i+=2)
	{
		if (!a[i])
		{
			nrsol++;
			for (j=i*2;j<=n;j+=i)
			{
				a[j] = true;
			}
		}
	}
	printf("%d\n",nrsol);

	return 0;
}