按照你的要求编写的Java程序如下
import java.util.ArrayList;
import java.util.List;
import javax.swing.JOptionPane;
public class MethodsForQuadratics {
public static void main(String[] args) {
JOptionPane.showMessageDialog(null,"This program is designed to calculate quadratic,calculating roots by entering coefficient A,B,and C");
try {
String userInput = JOptionPane.showInputDialog("Please define a coefficient A of a quadratic function");
double firstNumber = Double.parseDouble(userInput);
userInput = JOptionPane.showInputDialog("Please define a coefficient B of a quadratic function");
double secondNumber = Double.parseDouble(userInput);
userInput = JOptionPane.showInputDialog("Please define a coefficient C of a quadratic function");
double thirdNumber = Double.parseDouble(userInput);
List result= getQuadraticRoots1(firstNumber,secondNumber,thirdNumber);
String str="";
for(int i=0;i Imaginary imaginary=result.get(i);
if(imaginary.imaginary==0){
str=str+imaginary.real+"\n";
}else{
if(imaginary.imaginary>0)
str=str+imaginary.real+"+";
else
str=str+imaginary.real;
str=str+imaginary.imaginary+"i\n";
}
}
JOptionPane.showMessageDialog(null,"The first Quadratic,calculating root for A,B,C is:\n" + str);
} catch (Exception e) {
JOptionPane.showMessageDialog(null,"I'm sorry, it is not a valid input .");
}
}
public static List getQuadraticRoots1(double a, double b, double c){
Listlist=new ArrayList();
if (Math.sqrt(b*b-4*a*c)>=0) {
Imaginary imaginary1=new Imaginary();
imaginary1.real = (-b + Math.sqrt(b*b-4*a*c))/2*a;
list.add(imaginary1);
Imaginary imaginary2=new Imaginary();
imaginary2.real = (-b - Math.sqrt(b*b-4*a*c))/2*a;
list.add(imaginary2);
}else {
Imaginary imaginary1=new Imaginary();
imaginary1.real = -b/2*a;
imaginary1.imaginary=Math.sqrt(-(b*b-4*a*c))/2*a;
list.add(imaginary1);
Imaginary imaginary2=new Imaginary();
imaginary2.real = -b/2*a;
imaginary2.imaginary=-Math.sqrt(-(b*b-4*a*c))/2*a;
list.add(imaginary2);
}
return list;
}
}
class Imaginary{
double real;
double imaginary;
}
运行结果
