#include <iostream>
using namespace std;

double partA(const double& x, const size_t& N)
{
	double summary = x;
	double numerator = 1, denominator = 1;
	double xScale = 1;
	int scale = 2;
	for (size_t i = 1; i < N; i++)
	{
		xScale *= -x;
		numerator *= (scale - 1);
		denominator *= scale;
		const double temp = numerator / denominator * xScale;
		summary += temp;
		scale += 2;
	}
	return summary;
}

pair<double, size_t> partB(const double& x, const size_t& N, const double& e)
{
	double summary = 0;
	if (abs(x) > abs(e))
	{
		summary += x;
	}

	double numerator = 1, denominator = 1;
	double xScale = 1;
	int scale = 2;
	size_t amount = 0;
	for (size_t i = 1; i < N; i++)
	{
		xScale *= -x;
		numerator *= (scale - 1);
		denominator *= scale;
		const double temp = numerator / denominator * xScale;
		if (abs(temp) > abs(e))
		{
			summary += temp;
			amount++;
		}
		scale += 2;
	}
	return pair<double, size_t>(summary, amount);
}

int main()
{
	// Part1
	int nArraized[10];
	int N = 0;
	double e, x;
	cout << "Enter N, using 10 numbers: ";
	for (size_t i = 0; i < 10; i++)
	{
		cin >> nArraized[i];
		N += nArraized[i];
	}
	if (N <= 0)
	{
		cout << "N <= 0";
		return 0;
	}

	cout << "Enter x: ";
	cin >> x;

	cout << endl << "Result of A task is " << partA(x, N);

	// part 2
	double eps[10];
	cout << endl << "Enter 10 eps: ";
	for (size_t i = 0; i < 10; i++)
	{
		cout << endl << "[" << i << "]: ";
		cin >> eps[i];
		pair<double, size_t> response = partB(x, N, eps[i]);
		cout << endl << "Result for this eps is summary = " << response.first << " with amount = " << response.second <<
			endl;
	}

	// part 3
	double compareWith = partA(x, N);
	double compareTo = 1.0 / sqrt(1 + x);

	cout << "Absolute difference between 1/sqrt(1+x) and row is: " << abs(compareWith - compareTo);
	return 0;
}