Cod sursa(job #461776)

Utilizator gramatovici_paulGramatovici Paul gramatovici_paul Data 8 iunie 2010 16:34:47
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.32 kb
#include<stdio.h>
bool c[2000001];
int i,j,k,n;
int main()
{
	freopen("ciur.in","r",stdin);
	freopen("ciur.out","w",stdout);
	scanf("%d",&n);
	c[1]=true;
	for (i=2;i*i<=n;++i)
	    if (!c[i])
			for (j=i*i;j<=n;j+=i)
				c[j]=true;
	for  (i=2;i<=n;++i)
	    if (!c[i])
			++k;
	printf("%d",k);
    return 0;
}