Cod sursa(job #1856480)

Utilizator TherevengerkingSurani Adrian Therevengerking Data 24 ianuarie 2017 22:43:03
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include <iostream>

using namespace std;
const int Nmax=2000000+5;
int n;
bool c[Nmax];
int main()
{
    cin>>n;
    int nr=0;
    for(int i=2;i*i<=n;++i)
    {
        if(!c[i])
            for(int j=i*i;j<=n;j+=i)
                c[j]=1;
    }
    for(int i=2;i<=n;++i)
        if(!c[i])++nr;
    cout<<nr;
    return 0;
}