a simple command line program to solve quadratic equations

solveQE.java

package main;


import java.util.Scanner;


public class solverQE {
    static double A, B, C;

    public static void main(String[] args) {
        Scanner inpt = new Scanner(System.in);

        System.out.println("Enter the equation to solve in this order> ax2+bx+c=0");
        String equation =inpt.next().trim();
        Abc(equation);
        secondThird(equation);
        solve(A,B,C);


        //System.out.println("A:" +A+"  B: "+B+"  C: "+C);

    }

    static void Abc(String eqn) {
        String a;
        if (Character.isLetter(eqn.charAt(0))) {
            a = "1";
        } else {
            a = String.valueOf(eqn.charAt(0));
            for (int i = 1; i < eqn.length(); i++) {
                if (Character.isLetter(eqn.charAt(i))) {
                    A = Double.parseDouble(a);
                    break;

                } else {
                    a += String.valueOf(eqn.charAt(i));
                }

            }
        }
        A = Double.parseDouble(a);


    }

    static void secondThird(String eqn) {


        int pos;
        int singChB;
        big:
        for (int x = 0; x < eqn.length(); x++) {

            if (eqn.charAt(x) == '+' || eqn.charAt(x) == '-') {
                pos = x + 1;

                if(eqn.charAt(x)=='-'){
                singChB=-1;}
                else {
                    singChB=1;
                }

                if (Character.isLetter(eqn.charAt(pos))) {
                    B = singChB;
                    break;
                } else {
                    String b = String.valueOf(eqn.charAt(pos));
                    for (int j = pos + 1; j < eqn.length(); j++) {
                        if (Character.isLetter(eqn.charAt(j))) {
                            B = Double.parseDouble(String.valueOf(b))*singChB;
                            int signCh=j+1;
                            int gc = j + 2;
                            if (Character.isLetter(eqn.charAt(gc))) {
                                C = 1;
                                break;
                            } else {
                                String c = String.valueOf(eqn.charAt(gc));
                                for (int k = gc + 1; k < eqn.length(); k++) {
                                    if (eqn.charAt(k) == '=') {
                                        C = Double.parseDouble(String.valueOf(c));
                                        break;
                                    } else {
                                        c += String.valueOf(eqn.charAt(k));
                                    }
                                }
                                C = Double.parseDouble(String.valueOf(c));
                                if(eqn.charAt(signCh)=='-'){
                                    C=(C*-1);
                                }
                                  break big;
                            }
                        } else {
                            b += String.valueOf(eqn.charAt(j));
                        }
                    }
                    B = Double.parseDouble(String.valueOf(b))*singChB;

                }

            }
        }
    }
    static void solve(double x,double y,double z){
        double ans1,ans2;
        double ru=(y*y)-(4*x*z);
        ru=Math.sqrt(ru);
        double rd=2*x;
        ans1=((y*-1)+ru)/rd;
        ans2=((y*-1)-ru)/rd;

        printA(ans1,ans2);
    }

       static void printA(double a,double b){
           //double ans1d,ans2d;
           if((int)a==a&&(int)b==b) {
           System.out.println("x1 is: "+(int)a+" and x2 is: "+(int)b);
               return;
           }
               System.out.println("x1: "+a+" and x2: "+b);



    }


    }