#include <vector>

void sieve(std::vector<int>& primelist, int i)
{
    bool primes[i];

    primes[0] = false;
    primes[1] = false;

    for (int j = 2; j < i; j++)
        primes[j] = true;

    for (int j = 2; j * j < i; j++)
    {
        if (primes[j])
        {
            for (int k = j; k * j < i; k++)
                primes[k*j] = false;
        }
    }

    for (int k = 2; k < i; k++)
    {
        if (primes[k])
            primelist.push_back(k);
    }
}