Cod sursa(job #2010058)

Utilizator ioana04Adumitroaei Ioana ioana04 Data 11 august 2017 17:15:28
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.36 kb
Raporteaza aceasta sursa 
#include <fstream>

using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");

bool prim[2000003];

 int main()
{
    int n,i,j,ct;
    fin>>n;
    ct=1;
    for(i=3;i<=n;i+=2)
        if(prim[i]==0)
        {
         for(j=i+i+i;j<=n;j+=i)
           prim[j]=1;
          ct++;
        }
    fout<<ct;

    return 0;
}