Cod sursa(job #395827)
Utilizator | Data | 13 februarie 2010 20:32:57 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include <fstream>
using namespace std;
bool v[2000000001];
long n;
ifstream f("ciur.in");
ofstream o("ciur.out");
void ciur()
{
f>>n;
long c=0;
for (long i=2;i<=n;i++)
v[i]=false;
for (long i=2;i<=n;i++)
if (v[i]) {for (long j=i*2;j<=n;j++) v[j]=0;c++;}
o<<c;
}
int main()
{
ciur();
return 0;
}