Ciurul lui Eratostene

#include <iostream>
#include <math.h>
#define MAX 1000000
using namespace std;

int v[MAX];//presupunem ... toate prime

int main()
{
    int i, n, j;
    cout<<"n=";
    cin>>n;
    v[0]=v[1]=1;//NEPRIME
    for(i=2; i<=sqrt(n); i++)
    {
        if(v[i]==0)//daca v[i] e prim
        {
            for(j=2; i*j<=n; j++)
                v[i*j]=1;//este neprim
        }
    }
    for(i=1; i<=n; i++)
        if(!v[i])
            cout<<i<<" ";//toate numerele prime

    return 0;
}