C++ Babylonian Method – SQRT()

C++ implementation of Babylonian Method – method to calculate square root of positive numbers.

Enter number to square root: 3
Enter precision 0.0000000000001
sqrt(3) = 0.3
sqrt(3) = 5.15
sqrt(3) = 2.86626
sqrt(3) = 1.95646
sqrt(3) = 1.74492
sqrt(3) = 1.7321
sqrt(3) = 1.73205

#include <iostream>

// ? 2018 TheFlyingKeyboard and released under MIT License 
// theflyingkeyboard.net

using namespace std;

int main() {
  double number = 0.0;
  double precision = 0.0;

  cout << "Enter number to square root: ";
  cin >> number;

  cout << "Enter precision ";
  cin >> precision;

  if (number < 0) {
    cout << "number must be >= 0" << endl;
    return 1;
  }

  if (number == 0) {
    cout << "sqrt(0) = 0" << endl;
    return 0;
  }

  double x = number / 10;
  double y = number / x;

  do {
    cout << "sqrt(" << number << ") = " << x << endl;
    x = (x + y) / 2;
    y = number / x;
  } while (x - y > precision);

  int a;
  cin >> a;

  return 0;
}