Cod sursa(job #880913)
Utilizator | Data | 17 februarie 2013 15:21:38 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include <fstream>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
char v[2000000];
int main()
{
long int n, s=0;
in >> n;
for(int i=2;i<=n;i++)
if(!v[i])
{
s++;
for(int j=i*i;j<=n;j+=i)
v[j]=1;
}
out << s;
return 0;
}