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

class Quadratic {
public:
	Quadratic(double a, double b, double c);
	~Quadratic();
	void Solution();
private:
	double *x;
	double a;
	double b;
	double c;
};
Quadratic::Quadratic(double a, double b, double c) {
	x = new double[2];
	this->a = a;
	this->b = b;
	this->c = c;
};
Quadratic::~Quadratic() {
	delete[]x;
};
void Quadratic::Solution() {
	if (a == 0) {
		if (b == 0) {
			if (c == 0) {
				cout << "х - любой число!" << endl;
			}
			else {
				cout << "c!=0\n" << "Нет решений!" << endl;
			};
		}
		else {
			if (c == 0) {
				x[0] = (c / b);
				cout << "x=" << x[0] << endl;
			}
			else {
				x[0] = -(c / b);
				cout << "x=" << x[0] << endl;
			}
		};
	}
	else {
		double D;
		D = (b*b) - 4 * a*c;
		if (D >= 0) {
			if (b == 0) {
				if (c == 0) {
					cout << "x1=x2=0" << endl;
				}
				else {
					x[0] = (sqrt(D)) / (2 * a);
					x[1] = (-sqrt(D)) / (2 * a);
					cout << "x1=" << x[0] << endl << "x2=" << x[1] << endl;
				};
			}
			else {
				x[0] = (-b + sqrt(D)) / (2 * a);
				x[1] = (-b - sqrt(D)) / (2 * a);
				cout << "x1=" << x[0] << endl << "x2=" << x[1] << endl;
			}
		}
		else {
			if (b == 0) {
				cout << "x1=" << "+i*" << sqrt(abs(D)) / (2 * a) << endl;
				cout << "x2=" << "-i*" << sqrt(abs(D)) / (2 * a) << endl;

			}
			else {
				cout << "x1=" << (-b) / (2 * a) << "+i*" << sqrt(abs(D)) / (2 * a) << endl;
				cout << "x2=" << (-b) / (2 * a) << "-i*" << sqrt(abs(D)) / (2 * a) << endl;
			};
		};
	};
};

int main()
{
	double a;
	double b;
	double c;
	setlocale(LC_ALL, "ru");
	int menu;
	bool t = true;
	while (t) {
		cout << "ax^2+bx+c=0" << endl;
		cout << "1.Ввести коэффициенты с клавиатуры" << endl;
		cout << "2.Взять коэффициенты из файла" << endl;
		cout << "0.Выход" << endl;
		cin >> menu;
		switch (menu)
		{
		case 1: {
			system("cls");
			for (int i = 0; i < 3; i++)
			{
				if (i == 0) {
					cout << "Введите коэффициент а" << endl;
					cin >> a;
				}
				if (i == 1) {
					cout << "Введите коэффициент b" << endl;
					cin >> b;
				}
				if (i == 2) {
					cout << "Введите коэффициент c" << endl;
					cin >> c;
				};
			}
			Quadratic equation(a, b, c);
			equation.Solution();
			break;
		}
		case 2: {
			system("cls");
			fstream fs;
			fs.open("Text.txt", fstream::in);
			if (!fs.is_open()) {
				cout << "Файл не найден" << endl;
			}
			else {
				/*string str="";
				while (!fs.eof()) {

					getline(fs, str);
					if (str.find('a') != string::npos&&str.find(';') != string::npos) {
						a = stod(str.substr(str.find('=')+1, str.find(';') - (str.find('=')+1)));

					}
					if (str.find('b') != string::npos&&str.find(';') != string::npos) {
						b = stod(str.substr(str.find('=') + 1, str.find(';') - (str.find('=') + 1)));
					}
					if (str.find('c') != string::npos&&str.find(';') != string::npos) {
						c = stod(str.substr(str.find('=') + 1, str.find(';') - (str.find('=') + 1)));
					}
					cout << str << endl;
				}*/
				string str = "";
				char ch;
				vector<int> values;
				fstream fs;
				fs.open("Text.txt", fstream::in);
				while (!fs.eof()) {
					fs.get(ch);
					str = str + ch;
					if (ch == ' ') {
						if (str == " " || str == "" || str == "\0") {

						}
						else {
							values.push_back(stoi(str));
							str = "";
						}
					};
				}
				auto it = values.begin();
				if (values.size() < 3) {
					cout << "Недостаточно коэффициентов" << endl;
				}
				else {
					a = *it;
					++it;
					b = *it;
					++it;
					c = *it;
					values.erase(values.begin(),it);
				}

				Quadratic equation(a, b, c);
				equation.Solution();
			}

			break;
		}
		default:
			t = false;
			break;
		}

	}
}