#include <iostream>
#include <iomanip>
#include<cmath>
using namespace std;


void menu_print();
void root_num(double a, double b, double c);
void calc_root(double a, double b, double c);
void point_x(double a, double b, double c, double x);



int main() {
    menu_print();
return 0;
}


void menu_print(){
    double a, b, c, x;
    int opt=1;

    cout << "Enter the three parameters of a*x^2+b*x+c = 0\n";
    cout << "Enter a parameter: ";
    cin >> a;
    cout << "Enter b parameter: ";
    cin >> b;
    cout << "Enter c parameter: ";
    cin >> c;

    while(opt != 0) {
        cout << "0 - exit, 1 - roots, 2 - value at point x, 3- new equation\n";
        cin >> opt;
        if(opt == 0) {
            cout << "Exit! Bye\n";
            return;
        }
        if(opt == 1) { root_num(a, b, c); calc_root(a, b, c); }
        if(opt == 2) {
            cout << "Enter x value: ";
            cin >> x;
            point_x(a, b, c, x);
        }
        if(opt == 3) { menu_print(); }
    }
}



void root_num(double a, double b, double c){
    double delta = (b*b)-(4*a*c);
        if(delta<0)
        {
            cout<<"Equation doesn't have any roots."<<endl;
            return;
        }

        if(delta==0)
        {
            cout<<"The only root is: ";
            return;
        }

        if(delta>0)
        {
            cout<<"The two roots are: ";
        }
}

void calc_root(double a, double b, double c){
    double x1, x2, delta;
    delta = (b*b)-(4*a*c);
    if (delta == 0) {
        x1=-b/(2*a);
        cout << setiosflags(ios::fixed) << setprecision(1);
        cout << x1 << endl;
    }
    if (delta > 0){
        x1=(-b+sqrt(delta))/(2*a);
        x2=(-b-sqrt(delta))/(2*a);
        cout << x1 << " " << x2 << endl;
    }
}

void point_x(double a, double b, double c, double x){
    double sum;
    sum = (a*(pow(x,2)))+(b*x)+c;
    cout << "The result is " << sum << endl;
}