Cod sursa(job #1920431)

Utilizator tavisOctavian Matei tavis Data 10 martie 2017 00:37:34
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
int i,j,n,prim[2000000],cnt;
int main()
{
    ifstream in("ciur.in");
    ofstream out("ciur.out");
    in>>n;
    for(i=2;i<=n;i++)prim[i]=1;
    for(i=1;i<=n;i++){
        if(prim[i])
            {++cnt;
            for(j=i+i;j<=n;j+=i)
                prim[j]=0;
        }
    }out<<cnt;
}