testsAndMisc-archive/CPP/miscelanious/solveQuadraticEquation.cpp

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

const std::string ENTER = "Enter quadratic equation constants: ";
const std::string WHAT_TO_INPUT = "a, b, c as in: ax^2 + bx + c = 0";
const std::string START =  ENTER + WHAT_TO_INPUT;

void print(const std::string s) { std::cout << s << std::endl; }

float getDelta(float a, float b, float c)
{
	return b*b - 4*a*c;
}

float calculateFirstTerm(float a, float b, float delta)
{
	return (-b - sqrt(delta))/(2*a);
}

float calculateSecondTerm(float a, float b, float delta)
{
	return (-b + sqrt(delta))/(2*a);
}

int main()
{
	print(START);
	float a, b, c;
	std::cin >> a;
	std::cin >> b;
	std::cin >> c;
	float delta = getDelta(a, b, c);
	if(delta < 0) 
	{
		print("delta smaller than 0");
		return -1;
	}
	
	float x_1 = calculateFirstTerm(a, b, delta);
	float x_2 = calculateSecondTerm(a, b, delta);
	print("Solutions:");
	std::cout << "x_1 = " << x_1 << std::endl;
	std::cout << "x_2 = " << x_2 <<  std::endl;
	return 0;
	
	
}