Cod sursa(job #693246)
Utilizator | Data | 27 februarie 2012 11:26:01 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
bool v[2000001];
int i,n,nr,j;
int main()
{
f>>n;
for(i=2;i<=n;i++)
if(!v[i])
{
nr++;
for(j=i;j<=n;j=j+i)
v[j]=true;
}
g<<nr<<'\n';
f.close();
g.close();
return 0;
}