Cod sursa(job #905963)
Utilizator | Data | 6 martie 2013 12:52:10 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
using namespace std;
#include<fstream>
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int main()
{
int n, i, j, prim[2000005],contor=0;
fin>>n;
for(i=2;i<=n;i++)
{
if(prim[i]==0)
{ contor++;
for(j=i+i;j<=n;j=j+i)
prim[j]=1;
}
}
fout<<contor;
}