#include <fstream>
#include <iostream>
#include <string>
using namespace std;



double Epsilon(double LimitEps){
	double Eps = 0.0f;
	bool isCorrect = false;
	do
	{
		cin >> Eps;
		isCorrect = true;
		if ((Eps < LimitEps) && (Eps > 1))
		{
			isCorrect = false;
			cout << ("Your number must belong to the range of [ ") << LimitEps << (";") << 1 << (" ] ") << endl;

		}
	} while (!isCorrect);
	return Eps;
}

double FunctionArgument(double limitX) {
	double x = 0.0f;
	bool isCorrect = false;
	do
	{
		cin >> x;
		isCorrect = true;
		if ((x < 0) && (x > limitX))
		{
			isCorrect = false;
			cout << ("Your number must belong to the range of [ ") << 0 << (";") << limitX << (" ] ") << endl;

		}
	} while (!isCorrect);
	return x;
}

double MaclaurinSeries(double Eps, double x) {
	double y = 0.0, value = 0.0;
	double factorial = 1.0, power = x, sign = 1.0;
	int n = 1;
	do {
		value = power / factorial;
		y += sign * value;
		n++;
		sign *= -1.0;
		power *= x * x;
		factorial *= (double)(2 * n - 1) * (2 * n - 2);
	} while (value > Eps);
	return y;
}

void Input(double  Eps, double x, double result) {
	printf("%.4f ", Eps, x, result);
}

void saveResult(string result)
{
	bool AttemptOne = true;
	bool AttemptTwo = true;
	try {
		ofstream output;
		output.open("max.txt");
		if (output.is_open()) {
			output << result;
			output.close();
		}
		else {
			cout << "Ошибка. Проблема при записи результата!" << endl;
			AttemptOne = false;
		}
	}
	catch (ios_base::failure& f1) {
		cout << "Ошибка. Проблема при записи результата!" << endl;
		AttemptTwo = false;
	}
}

int main()
{
	const double LimitEps = 0.000001;
	const double LimitX = 124.0;
	double y, Eps, x;
	cout << "\nThis program calculates the value of a function y = sin(x) with precision e by expanding the function in a Maclaurin series.\n";
	cout << "\nEnter the precision value:\n";
	Eps = Epsilon(LimitEps);
	cout << "\nEnter the value of the function argument:\n";
	x = FunctionArgument(LimitX);
	y = MaclaurinSeries(Eps, x);
	Input(Eps, x, y);
	void saveResult(string result);
	return 0;
}