// Program to find the square root of a number
#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;
const int		MAXTIMES = 50;
const double	EPSILON = 1.0e-012;

int main ()
{
	double		trialx;			// Trial square root
	double		nextTrial;		// Next trial root 
	double		number;			// Number to take sq. root of
	double		diff = 1.0;		// Change in root value
	int			count = 1;		// Loop count

		// Get starting values
	cout << "Number to take square root of: ";
	cin >> number;
	cout << endl << "Using Newton's Method" << endl 
		<< "Initial" << " trial for root: ";
	cin >> trialx;
	nextTrial = 0.5 * (trialx + number / trialx);
		// Start table for output
	cout << "Count    Trial root of " << number << endl;
	cout << scientific << showpoint;
	while (count < MAXTIMES && fabs(diff) > EPSILON)
	{
		diff = trialx - nextTrial;
		cout << setw(5) << count << setprecision(12) << setw(22)
			<< trialx << endl;
			// Get next estimate
		trialx = nextTrial;
		nextTrial = 0.5*(trialx+number / trialx);
		count++;
	}
	cout << setw(5) << count <<setprecision(12) << setw(22)
		<< trialx << endl;
	return 0;
}