Cod sursa(job #770148)
Utilizator | Catalin Gabriel Dragomirescu catalin11gabriel | Data | 22 iulie 2012 12:33:17 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 20 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.37 kb |
#include <fstream>
using namespace std;
int main ()
{
int n,i,j,v[10001],nr=1;
ifstream fcin ("ciur.in");
ofstream fcout ("ciur.out");
fcin>>n;
for (i=3;i<=n;i+=2)
v[i]=1;
for (i=3;i<=n;i+=2)
if (v[i]==1)
for (j=2*i;j<=n;j+=i)
v[j]=0;
for (i=3;i<=n;i+=2)
if (v[i]==1)
nr++;
fcout<<nr;
fcin.close ();
fcout.close ();
return 0;
}