基础练习 矩形面积交

import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.Scanner;  

    public class Main{   
        public static void main(String[] args){  
            Scanner input = new Scanner(System.in);
            double a1,a2,b1,b2;
            double x1,x2,y1,y2;
            a1 = input.nextDouble();
            b1 = input.nextDouble();
            a2 = input.nextDouble();
            b2 = input.nextDouble();
            x1 = input.nextDouble();
            y1 = input.nextDouble();
            x2 = input.nextDouble();
            y2 = input.nextDouble();
            double n1,m1,n2,m2;
            n1 = Math.max(Math.min(x1, x2), Math.min(a1, a2));
            m1 = Math.max(Math.min(y1, y2), Math.min(b1, b2));
            n2 = Math.min(Math.max(x1, x2), Math.max(a1, a2));
            m2 = Math.min(Math.max(y1, y2),Math.max(b1, b2));
            if(n2>n1&&m2>m1){
                NumberFormat format = new DecimalFormat("#.00");
                System.out.println(format.format((m2-m1)*(n2-n1)));
                
            }
            else{
                System.out.println("0.00");
            }
            
        }
 }