Cod sursa(job #217107)

Utilizator DanFFodorean Dan DanF Data 27 octombrie 2008 00:08:57
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.29 kb
#include "fstream.h"
#include "math.h"
int main()
{long n,s=0,i,j;
 char prim[2000005];
 ifstream f("ciur.in");
 ofstream g("ciur.out");
 f>>n;
 for(i=2;i<=n;i++)
  prim[i]=1;
 for(i=2;i<=n;i++)
  if(prim[i])
  {s++;
   for(j=i+i;j<=n;j+=i)
    prim[j]=0;
  }
 g<<s;
return 0;
}