Cod sursa(job #902468)

Utilizator DanyPrvPirvoaica Daniel DanyPrv Data 1 martie 2013 14:26:35
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
#include <stdio.h>
using namespace std;
FILE *f=fopen("ciur.in","r"),
    *g=fopen("ciur.out","w");
int n,i,j,nr;
char a[2000000];
int main()
{
    fscanf(f,"%d",&n);
    for(i=2;i<=n;i++){
        if(a[i]==0){
            nr++;
            for(j=i;j<=n;j+=i)
                a[j]=1;
        }
    }
    fprintf(g,"%d",nr);
    return 0;
}