saknies traukimas

#include <iostream>
#include <fstream>
#include <cmath>
#include <iomanip>

using namespace std;

int main()
{
    int n;
    double a = 1.0, precision = 0.000001, b;


    ifstream fr ("U1.txt");
    ofstream fw ("U1rez.txt");
    fr >> n;


    while (a * a != n)
    {
        b = n / a;
        a =(a + b) / 2;

        if (a < precision)
        {
            break;
        }


    }


    fw << fixed << setprecision(6) << a;

    fr.close();
    fw.close();

}