Cod sursa(job #439421)

Utilizator siminescuPaval Cristi Onisim siminescu Data 11 aprilie 2010 16:06:21
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.32 kb
Raporteaza aceasta sursa 
#include<stdio.h>
int n,nr;
char v[2000002];
int main()
{
	freopen("ciur.in","r",stdin);
	freopen("ciur.out","w",stdout);
	scanf("%d",&n);
	int i,j;
	for(i=2;i<=n/2;i++)
		if(v[i]==0)
		{
			for(j=i;j<=n;j=j+i)
				v[j]=1;
			nr++;
		}
	for(i=n/2+1;i<=n;i++)
		if(v[i]==0)
			nr++;
	printf("%d",nr);
}