Cod sursa(job #543127)
Utilizator | Data | 27 februarie 2011 16:24:21 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.25 kb |
#include<fstream.h>
ifstream f("ciur.in");
ofstream g("ciur.out");
long v[2000001],i,n,y,nr;
int main ()
{
f>>n;
for(i=2;i<=n;i++)
if(v[i]==0) {nr++;
y=2;
while(y*i<=n) v[y*i]=1,y++;
}
g<<nr;
f.close();
g.close();
return 0;
}