Cod sursa(job #662717)
Utilizator | Data | 16 ianuarie 2012 22:23:20 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 40 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include<fstream>
using namespace std;
unsigned int n,i,j,nr;
bool uz[2000001];
int main()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
for(i=2;i<=n;++i)
{
if(!uz[i])
++nr;
for(j=i+i;j<=n;j+=i)
uz[j]=1;
}
printf("%d",nr);
return 0;
}