Cod sursa(job #1389704)

Utilizator Daria09Florea Daria Daria09 Data 16 martie 2015 15:49:38
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.32 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int n,a[2000001],i,j,nr;
int main()
{
   f>>n;
   for(i=2;i<=n;i+=2)a[i]=1; nr=1;
   for(i=3;i<=n;i+=2)
          if(a[i]==0)
              { nr++; for(j=i*2;j<=n;j+=i)a[j]=1;}
   g<<nr;
    return 0;
}