Cod sursa(job #300739)

Utilizator curcubeuPop Simina curcubeu Data 7 aprilie 2009 17:25:40
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
#include<fstream.h>
char prim[2000010];
long nr=0,i,j,n;
ifstream f("ciur.in");
ofstream g("ciur.out");
int main()
{
    f>>n;
    prim[1]=0;
    for(i=2;i<=n;i++)
    prim[i]=1;
    for(i=2;i<=n;i++)
    if(prim[i])
    for(j=i+i;j<=n;j+=1)
    prim[j]=0;
    
    for(i=1;i<=n;i++)
    if(prim[i]) nr++;
    g<<nr;
    return 0;
}