Cod sursa(job #622127)

Utilizator masterchiefSabin Olaru masterchief Data 17 octombrie 2011 14:24:29
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.32 kb
Raporteaza aceasta sursa 
#include<cstdio>
using namespace std;
int n,i,j,nr=0;
bool a[2000000];
int main()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
for(i=2;i*i<= n;++i)
	if(!a[i])
for (j=i*i;j<=n;j+=i)
    a[j]=true;
for (i=2;i<=n;++i)
    if(!a[i])
       nr++;
printf("%d",nr);
return 0;
}