lab1 milestone

lab1/CMakeLists.txt

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+CMAKE_MINIMUM_REQUIRED(VERSION 3.20)
+
+project(LAB1 CXX)
+
+add_executable(LAB1 lab1.cpp)

lab1/lab1.cpp

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+#include <iostream>
+#include <array>
+#include <cmath>
+#include <fstream>
+
+std::array<double, 3> read_polynom_from_file() {
+	std::array<double, 3> to_return{};
+	std::ifstream input("input.txt");
+
+	if (!input.is_open()) {
+		std::cerr << "Error: Could not open input file" << std::endl;
+		exit(1);
+	}
+
+	input >> to_return[0] >> to_return[1] >> to_return[2];
+	return to_return;
+}
+
+void solve_and_write_equation(const std::array<double, 3>& equation) {
+	std::ofstream output("output.txt");
+
+	if (!output.is_open()) {
+		std::cerr << "Error: Could not open output file" << std::endl;
+		exit(1);
+	}
+
+	// Count discriminant
+	double discr = equation[1]*equation[1]-4*equation[0]*equation[2];
+
+	if(discr < 0) {
+		output << "There is no roots in real numbers" << std::endl;
+		return;
+	}
+
+	if(discr == 0) {
+		double root = (-equation[1]+std::sqrt(discr))/(2*equation[0]);
+		output << "There is only one root in real numbers: " << root << std::endl;
+		return;
+	}
+
+	// 2 roots
+	double sqrt_discr = std::sqrt(discr);
+	double denominator = 2*equation[0];
+	double root1 = (-equation[1] + sqrt_discr) / denominator;
+	double root2 = (-equation[1] - sqrt_discr) / denominator;
+	output << "There are two real roots: " << root1 << "; " << root2 << std::endl;
+}
+
+int main() {
+	std::cout << "Lab 1 by Krutyanscky RI" << std::endl;
+	const auto eq = read_polynom_from_file();
+	solve_and_write_equation(eq);
+	return 0;
+}