Cod sursa(job #1860821)

Utilizator RaduhhRadu Flocea Raduhh Data 28 ianuarie 2017 13:31:58
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.33 kb
#include <fstream>

using namespace std;

long long i,j,n,k;
bool t[2000002];

int main() {
    ifstream cin("ciur.in");
    ofstream cout("ciur.out");
    cin>>n;
    for (i=2; i<=n; i++)
    if (!t[i])
    for (j=2; j<=n/i; j++)
        t[i*j]=true;
    for (i=2; i<=n; i++)
    if (!t[i]) k++;
    cout<<k;
    
}