Cod sursa(job #879500)
Utilizator | Data | 15 februarie 2013 15:17:17 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
using namespace std;
#include<fstream>
ifstream fin("ciur.in");
ofstream fout("ciur.out");
char v[2000005];
long long n,i,j,c;
int main()
{
fin>>n;
for(i=2;i<=n;i++)
if(!v[i])
{
c++;
for(j=i*i;j<=n;j=j+i)
v[j]=1;
}
fout<<c;
return 0;
}