#include "mysqrt.h"

using namespace std;
double mysqrt(double x)
{
    bool goodenough = false;
    double guess;
    double last = 0.0;

    if (x <= 0)
        return x;

    while (!goodenough) {
        guess = (last + (x / last)) / 2.0;
        last = guess;

        goodenough = abs(guess - last) <= 0.000000001;
    }
    return guess;
}