cpp_int gmp naiwny rozklad

#include <iostream>
#include <random>
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/gmp.hpp>
#include <boost/multiprecision/cpp_int/literals.hpp>
#include <boost/math/constants/constants.hpp>
#include <functional>



#include <chrono>
#include <random>
#include <iostream>
#include <thread>
#include <map>


using namespace std;

using namespace boost::multiprecision;
using namespace boost::multiprecision::literals;


class stoper
{
    chrono::time_point<chrono::high_resolution_clock> a,b;
public:
    void start(){a = chrono::high_resolution_clock::now();}
    void stop() {b = chrono::high_resolution_clock::now();}
    double value()
    {
        chrono::duration<double> elapsed_seconds = b-a;
        return elapsed_seconds.count();
    }
    void show()
    {
        cout << value()<<"s "<<endl;
    }
};


template <typename T>
void factor( T x)
{
    while ((x % 2) == 0) {
        x /= 2;
        std::cout << 2 << " ";
    }
    T i = 3;
    T e = sqrt(x);
    while (i <= e) {
        while ((x % i) == 0) {
            x /= i;
            e = sqrt(x);
            std::cout << i << " ";
        }
        i+=2;
    }
    if (x > 1)
        std::cout << x << " ";
}

template <typename T>
void factor2( T x)
{
    while ((x % 2) == 0) {
        x /= 2;
        std::cout << 2 << " ";
    }
    T i = 3;
    T e = sqrt(x);
    while (i <= e) {
        T q,r;
        divide_qr(x,i,q,r);
        while (r== 0) {
            x = q;
            divide_qr(x,i,q,r);
            std::cout << i << " ";
            e = sqrt(x);
        }
        i+=2;
    }
    if (x > 1)
        std::cout << x << " ";
}


template <typename T>
void factor3( T x)
{
    while ((x % 2) == 0) {
        x /= 2;
        std::cout << 2 << " ";
    }
    T i = 3;
    T e = sqrt(x);
    while (i <= e) {
        T q,r;
        bool change=false;
        divide_qr(x,i,q,r);
        while (r== 0) {
            x = q;
            divide_qr(x,i,q,r);
            std::cout << i << " ";
            change=true;
        }
        if (change) e = sqrt(x);
        i+=2;
    }
    if (x > 1)
        std::cout << x << " ";
}


template <typename T, typename F >
void test( F fun  )
{
    T a("5742507205757425072053");
    stoper s;
    s.start();
    fun(a);
    s.stop();
    s.show();
}

int main()
{
    test<cpp_int>(factor<cpp_int>);
    test<mpz_int>(factor<mpz_int>);

    test<cpp_int>(factor2<cpp_int>);
    test<mpz_int>(factor2<mpz_int>);

    test<cpp_int>(factor3<cpp_int>);
    test<mpz_int>(factor3<mpz_int>);


}