psds-cpp-2025/01_week/tasks/quadratic/quadratic.cpp at 2ed52ca3c9620c911b1d1f47c565e57b4181b523 · psds-cpp/psds-cpp-2025 · GitHub

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#include <iostream>
#include <iomanip>
#include <cmath>
#include <utility>

void SolveQuadratic(int a, int b, int c) {
    std::cout << std::setprecision(6);

    if (a == 0 && b == 0 && c == 0) {
        std::cout << "infinite solutions";
        return;
    }

    if (a == 0 && b == 0 && c != 0) {
        std::cout << "no solutions";
        return;
    }

    if (a == 0) {
        double root = -static_cast<double>(c) / b;

        if (root == 0.0) root = 0.0;

        std::cout << root;
        return;
    }

    double discr = static_cast<double>(b) * b - 4.0 * a * c;

    if (discr < 0) {
        std::cout << "no solutions";
        return;
    }

    if (discr == 0) {
        double root = -static_cast<double>(b) / (2.0 * a);

        if (root == 0.0) root = 0.0;

        std::cout << root;
        return;
    }

    double sqrt_d = std::sqrt(discr);
    double root1 = (-static_cast<double>(b) - sqrt_d) / (2.0 * a);
    double root2 = (-static_cast<double>(b) + sqrt_d) / (2.0 * a);

    if (root1 > root2) {
        std::swap(root1, root2);
    }

    if (root1 == 0.0) root1 = 0.0;
    if (root2 == 0.0) root2 = 0.0;

    std::cout << root1 << " " << root2;
}