lesson19_322

#include <iostream>

using namespace std;

void sum(int a, int b) {
    b = 17;
    cout << a << " " << b << endl;
}

int solve_eq(double coeff[], double sol[]) {
    // returns number of roots
    // koeff = {a, b, c}
    // a * x * x + b * x + c = 0, sol = {x1, x2}
    const double a = coeff[0],
        b = coeff[1],
        c = coeff[2];
    double eps = DBL_EPSILON; // 1.0e-10;//_DOUBLE_EPS;
    if (abs(a) <= eps) {
        sol[0] = -c / b;
        return 1;
    }
    // discriminant
    double d = b * b - 4 * a * c;
    if (d < 0) {
        return 0;
    }
    d = sqrt(d);
    sol[0] = (-b - d) / (2 * a);
    sol[1] = (-b + d) / (2 * a);
    return 2;
}

double check_solve_eq(double coeff[], double x) {
    const double a = coeff[0],
        b = coeff[1],
        c = coeff[2];
    return a * x * x + b * x + c;
}

void analitic_task() {
    double abc[]{-1, -2, -5};
    double xs[2];
    int num = solve_eq(abc, xs);

    for (int k = 0; k < num; k++)
        cout << "root: " <<  xs[k] << " "
             << "precision: "
             << check_solve_eq(abc, xs[k]) << endl;
    cout << endl;
}

double check_function(double params[], double x) {
    return params[0] * tan(params[1] * x) - params[2];
}

void numeric_task() {
    // function(x)
    double p[]{1.1, 0.5, 10};
    double val;
    double sol = -100;
    double min = abs(check_function(p, sol));
    for (double x = -100; x <= 100; x += 0.00001) {
        val = check_function(p, x);
        if (abs(val) < min) {
            min = abs(val);
            sol = x;
        }
        //if(abs(val) < 0.02)
        //  cout << x << " " << val << endl;
    }
    cout << sol << " " << min << endl;
}

void test_colors() {
    cout << "\033[33mTest" << endl;
    cout << "Hoba";
    for (int id = 0; id <= 108; id++) {
        cout << "\033[" << id << "m "
            << id << "\033[0m";
        if ((id + 1) % 20 == 0)
            cout << endl;
    }
    cout << endl;
    cout << "\033[41;32m GOOD DAY \033[0m" << endl;
}

int main() {
    //analitic_task();
    //numeric_task();
    /*
    int a = 4;
    int b = -4;
    sum(a, b);
    cout << a << " " << b << endl;
    */
    test_colors();

    return 0;
}