CPP-07-Quadratic-Equation.txt

/*
1. Define headers
2. Define class quadratic with private variables and public functions
3. Define input() function to get user input
4. Define compute() function to calculate the roots
	-> calculate discriminant value
	-> if d==0, then roots are equal (r1=r2)
	-> if d>0, then roots are real and distinct
	-> if d<0, then roots are complex
5. Define output() function to display result
6. Define main() function to invoke all class functions
*/

#include<iostream>
#include<math.h>

using namespace std;

class quadratic {
    private:
        double a,b,c,d,r1,r2;
    public:
        void input();
        void compute();
        void output();
};

void quadratic::input(){
    cout<<"Enter the co-efficients of a,b,c";
    cin>>a>>b>>c;
}

void quadratic::compute(){
    d= b*b - 4*a*c;
    if(d==0)
    {
        cout<<"Roots are equal"<<endl;
        r1= -b / (2*a);
        r2=r1;
    }
    else if(d>0){
        cout<<"Roots are real and distinct"<<endl;
        r1=(-b + sqrt(d)) / (2*a);
        r2=(-b - sqrt(d)) / (2*a);
    }
    else {
        cout<<"Roots are imaginary"<<endl;
        exit(0);
    }
}


void quadratic::output(){
    cout<<"First root = "<<r1<<endl;
    cout<<"Second root = "<<r2<<endl;
}

int main(){
    quadratic q;
    q.input();
    q.compute();
    q.output();
}