Cod sursa(job #2380786)

Utilizator SirbuEdiSirbu Eduard SirbuEdi Data 15 martie 2019 15:09:31
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.33 kb
#include <fstream>

using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
bool v[2000004];
int main()
{
    int n,i,j,c=1;
    in>>n;
    for(i=3;i<=n;i+=2)
        if(v[i]==0)
        {
            c++;
            for(j=i*2;j<=n;j+=i)
                v[j]=1;
        }
    out<<c;

    return 0;
}