/* A different binary search -- find zeroes of a monotonic function */

#include <iostream>
#include <cmath>

using namespace std;

double function(double x) // any monotonic increasing function
{
	return x*x*x-27;
}

int main()
{
	const double error =0.00001;

	double low =0.0;  // function(low) <=0
	double high = 100.0; // function(high) >=0

	while (high - low > error )
	{
		cout << low << " .. " << high<<endl;
		double mid = (low+high)/2;

		if( function(mid) < 0 )
			low = mid;
		else
			high = mid;

	}

}