Cod sursa(job #352457)

Utilizator robigiirimias robert robigi Data 1 octombrie 2009 21:20:57
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.35 kb
#include <fstream>

using namespace std;

ifstream f ("ciur.in");
ofstream g ("ciur.out");

int n, nr;
char v[2000001];

int main()
{   f >> n;
    for (int i=3; i<=n; i+=2)
        if (!v[i])
        {   nr++;
            for (int j=i*2; j<=n; j+=i)
                v[j]=1;
        }
    g << nr+1 ;
    return 0;
}