Cod sursa(job #1165620)

Utilizator gbibBacotiu Gabi gbib Data 2 aprilie 2014 19:46:51
Problema Ciurul lui Eratosthenes Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
#include <fstream>

using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
int v[2000001];
int main()
{int i,j,n,c=0;
in>>n;
for(i=2;i*i<=n;i++)

    if(v[i]==0)
        {
    for(j=2*i;j<=n;j=j+i)
        v[j]=1;}
for(i=2;i<=n;i++)
    if(v[i]==0) c++;
out<<c<<endl;
    return 0;
}