Java学习手手记-一元二次函数解法

package com.method.main;

import java.util.Scanner;

public class main {
    public static void main(String[] args){
        double a,b,c;
        Scanner sc =new Scanner(System.in);
        System.out.print("Please put data in  a=");
        a=sc.nextDouble();
        System.out.print("Please put data in  b=");
        b=sc.nextDouble();
        System.out.print("Please put data in  c=");
        c=sc.nextDouble();
        double dt,sqrtdt;
        dt=b*b-4*a*c;
        if(dt<0){
            System.err.println("Wrong Data!Check out you data please!\nError:△<0");
            return;
        }else{
            sqrtdt=Math.sqrt(dt);
        }
        double x1,x2;
        x1 = (-b+sqrtdt)/(2*a);
        x2 = (-b-sqrtdt)/(2*a);
        if(x1==x2){
            System.out.println("The same answer/nThe answer is "+x1);
        }else{
            System.out.println("The different answer\nThe answer is x1="+x1+",x2="+x2);
        }

    }

}