Cod sursa(job #551488)
Utilizator | FMI - GabrielG GaborGabriel | Data | 10 martie 2011 20:21:37 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
#include <fstream.h>
ifstream f("ciur.in");
ofstream g("ciur.out");
int n,a=1,i,j;
bool v[2000005];
int main()
{
f>>n;
for(i=2;i<=n;i++)
{
if(v[i]==false)
{
a++;
for(j=2*i;j<=n;j+=i)
v[j]=true;
}
}
g<<a<<'\n';
f.close();
g.close();
return 0;
}