Cod sursa(job #240805)
Utilizator | Data | 8 ianuarie 2009 18:59:39 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include<fstream.h>
int v[2000010],i,n,nr=0,j;
int main()
{
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<=n;i++)
{ if(!v[i])
for(j=i+i;j<=n;j+=i)
v[j]=1;
}
for(i=2;i<=n;i++) if(!v[i]) nr++;
g<<nr;
f.close();
g.close();
return 0;
}