#include <iostream>
#include <math.h>

using namespace std;

double equation (double x)
{
	return x*x*x + x * x - 4*x - 4;
}

double derivative1 (double x)
{
	return 3*x*x + 2*x - 4;
}

double derivative2 (double x)
{
	return 6*x + 2;
}

namespace methods
{
	double chord (double a, double b, double accuracy=0.001)
	{
		double result;

		if (fabs(equation(a)) < accuracy)
		{
			return a;
		}

		if (fabs(equation(b)) < accuracy)
		{
			return b;
		}

		double c = a - (equation(a)*(b-a)/(equation(b)-equation(a)));

		if (fabs(equation(c)+equation(a)) < fabs(equation(c))+fabs(equation(a)))
		{
			result = chord(a, c, accuracy);
		}
		else
		{
			result = chord(c, b, accuracy);
		}

		return result;
	}

	double newton (double a, double b, double accuracy=0.001)
	{
		double c = (equation(a) * derivative2(a) > 0) ? a : b;

		while (fabs(equation(c)) > accuracy)
		{
			c = c - equation(c) / derivative1(c);
		}

		return c;
	}

	double modifiedNewton (double a, double b, double accuracy=0.001)
	{
		double c = (equation(a) * derivative2(a) > 0) ? a : b;
		double d = derivative1(c);

		while (fabs(equation(c)) > accuracy)
		{
			c = c - equation(c) / d;
		}

		return c;
	}

	double combined (double a, double b, double accuracy=0.001)
	{
		if (equation(a) < equation(b)) swap(a,b);

		while (fabs(a - b) > accuracy)
		{
			a = a - equation(a) / (derivative1(a) - equation(a)) * (b - a);
			b = b - equation(b) / derivative1(b);
		}

		return (a + b) / 2;
	}
}


int main ()
{
	double a;
	double b;
	double accuracy;

	cout << "Введите интервал для поиска корня (a b): ";
	cin >> a >> b;

	if (a > b) swap(a, b);

	cout << "Введите точность: ";
	cin >> accuracy;

	cout << endl;

	cout << "Результаты:\n";
	cout << "Метод хорд: " << methods::chord(a, b, accuracy) << endl;
	cout << "Метод касательных: " << methods::newton(a, b, accuracy) << endl;
	cout << "Модифицированный метод Ньютона: " << methods::modifiedNewton(a, b, accuracy) << endl;
	cout << "Комбинированный метод: " << methods::combined(a, b, accuracy) << endl;

	return 0;
}