Cod sursa(job #153447)

Utilizator sigridMaria Stanciu sigrid Data 10 martie 2008 15:45:12
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.32 kb
Raporteaza aceasta sursa 
#include<fstream.h>
#define dim 2000001
char prim[dim];
unsigned long cont,n;
ifstream f("ciur.in");
ofstream g("ciur.out");
int main()
{unsigned long i,j;
f>>n;
f.close();

for(i=2;i<=n;i++)
 if(!prim[i])
   {cont++;
    for(j=i+i;j<=n;j+=i)
     prim[j]=1;
   }

g<<cont<<'\n';
g.close();
return 0;
}