Cod sursa(job #1374432)

Utilizator DajAlecsandruPopescu Ioan DajAlecsandru Data 5 martie 2015 09:13:56
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin ("ciur.in");
ofstream fout ("ciur.out");
int i,a[2000005],k,j,n;
int main()
{
    fin >> n;
    k=1;
    for (i=3;i<=n;i=i+2)
         if (a[i]!=1)
          {k++;
           for (j=2*i;j<=n;j+=i)
             a[j]=1;
          }
   fout << k;

    return 0;
}