#include <iostream>
#include <vector>
#include <cmath>

#define INF ((float)(1e+300 * 1e+300)) 

std::vector<std::pair<std::string, double>> MidValue(double AB, double BC, double AC);
bool IsPossible(double AB, double BC, double AC);

int main()
{
	setlocale(LC_ALL, "ru-RU");
	double AB = 0, BC = 0, AC = 0;

	std::cout << "AB = ";
	std::cin >> AB;
	std::cout << "BC = ";
	std::cin >> BC;
	std::cout << "AC = ";
	std::cin >> AC;

	if (IsPossible(AB, BC, AC))
	{
		auto vec = MidValue(AB, BC, AC);

		for (size_t i = 0; i < vec.size(); ++i)
		{
			if (vec[i].second != INF)
			{
				std::cout << vec[i].first << "M" << i + 1 << " = " << vec[i].second << std::endl;
			}
			else
			{
				std::cout << vec[i].first << "M" << i + 1 << " --  Несуществует!" << std::endl;
			}
		}
	}
	else
	{
		std::cout << "Треугольник с такими сторонами не существует!" << std::endl;
	}

	system("pause");
	return 0;
}

bool IsPossible(double AB, double BC, double AC)
{
	if ((AB + BC > AC) && (AB + AC > BC) && (AC + BC > AB))
	{
		return true;
	}

	return false;
}

std::vector<std::pair<std::string, double>> MidValue(double AB, double BC, double AC)
{
	std::vector<std::pair<std::string, double>> vec;
	vec.reserve(3);

	std::pair<std::string, double> midAB;
	std::pair<std::string, double> midBC;
	std::pair<std::string, double> midAC;

	midAB.first = "A";
	double ABM = round(2 * (pow(AC, 2))) + (2 * (pow(BC, 2))) - (2 * (pow(AB, 2)));
	if (ABM >= 0)
	{
		midAB.second = (0, 5) * sqrt(ABM);
	}
	else
	{
		midAB.second = INF;
	}
	midBC.first = "B";
	double BCM = round(2 * (pow(AB, 2))) + (2 * (pow(AC, 2))) - (2 * (pow(BC, 2)));
	if (BCM >= 0)
	{
		midBC.second = (0, 5) * sqrt(BCM);
	}
	else
	{
		midBC.second = INF;
	}
	midAC.first = "C";
	double ACM = round((2 * (pow(AB, 2))) + (2 * (pow(BC, 2))) - (2 * (pow(AC, 2))));
	if (ACM >= 0)
	{
		midAC.second = (0, 5) * sqrt(ACM);
	}
	else
	{
		midAC.second = INF;
	}
	vec.push_back(midAB);
	vec.push_back(midBC);
	vec.push_back(midAC);

	return vec;
}