不知道在怎么改,第三条要求没实现

package com.sun;

public class Car {
    int number;
    public String name;
    public int rent;
    
}
package com.sun;

public class PassengerCar extends Car {
    private int peopleCapacity;
    public PassengerCar(){
        
    }
    public PassengerCar(int number,String name,int rent,int peopleCapacity){
        this.number=number;
        this.name=name;
        this.rent =rent;
        this.setPeopleCapacity(peopleCapacity);
        
    }
    public double getPeopleCapacity() {
        return peopleCapacity;
    }
    public void setPeopleCapacity(int peopleCapacity) {
        this.peopleCapacity = peopleCapacity;
    }

}
package com.sun;

public class Trunk extends Car {
    private int cargoCapacity;
    public Trunk(int number,String name,int rent,int cargoCapacity){
        this.number=number;
        this.name =name;
        this.rent =rent;
        this.setCargoCapacity(cargoCapacity);
        
    }
    public double getCargoCapacity() {
        return cargoCapacity;
    }
    public void setCargoCapacity(int cargoCapacity) {
        this.cargoCapacity = cargoCapacity;
    }

}

package com.sun;

public class PickUp extends Car {
    private int peopleCapacity;
    private int cargoCapacity;
    public PickUp(int number,String name,int rent,int peopleCapacity,int cargoCapacity){
        this.number=number;
        this.name=name;
        this.rent =rent;
        this.peopleCapacity=peopleCapacity;
        this.cargoCapacity=cargoCapacity;
        
    }
    public double getPeopleCapacity() {
        return peopleCapacity;
    }
    public void setPeopleCapacity(int peopleCapacity) {
        this.peopleCapacity = peopleCapacity;
    }
    public double getCargoCapacity() {
        return cargoCapacity;
    }
    public void setCargoCapacity(int cargoCapacity) {
        this.cargoCapacity = cargoCapacity;
    }

}

package com.sun;
import java.util.*;
public class Demo {
    
    @SuppressWarnings("resource")
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int sum = 0;
        int j=0;
  
      Car[] carsForRent={new PassengerCar(1,"奥迪A4",500,4),new 
PassengerCar(2,"马自达6",400,4),new PickUp(3,"皮卡雪6",450,4,2),new 
PassengerCar(4,"金龙",800,20),new Trunk(5,"松花江",400,4),new 
Trunk(6,"依维柯",1000,20)};
        System.out.println("欢迎使用答答租车系统\n您是否要租车：1 是 0否");
        Scanner input=new Scanner(System.in);
        switch(input.nextInt()){
        case 0:
            System.out.println("谢谢使用");
            break;
        case 1:
            System.out.println("您可租车的类型及其价目表：\n序号\t汽车名称\t租金\t容量");
            for(Car car: carsForRent){
                if(car instanceof PassengerCar){
                    PassengerCar c=(PassengerCar) car;
                System.out.println(car.number+"\t"+car.name+"\t"+car.rent+"元/天\t载人："+c.getPeopleCapacity()+"人");
                }
                if(car instanceof PickUp){
                    PickUp p=(PickUp) car;
  
                 
 System.out.println(car.number+"\t"+car.name+"\t"+car.rent+"元/天\t载
人："+p.getPeopleCapacity()+"人 载货： "+p.getCargoCapacity()+"吨");
                    }
                if(car instanceof Trunk){
                    Trunk t=(Trunk) car;
                    System.out.println(car.number+"\t"+car.name+"\t"+car.rent+"元/天\t载货： "+t.getCargoCapacity()+"吨");
                    }
                }
                 System.out.println("请输入您要租汽车的数量：");
                int n=input.nextInt();
                for(int i=1;i<=n;i++){
                    System.out.println("请输入第"+i+"辆车的序号：");
                    j=input.nextInt();
                    for(Car car: carsForRent){
                    if(j==car.number)
                        sum+=car.rent;
                    }    
                }    
            }
        System.out.println("请输入租车天数：");
        int k=input.nextInt();    
        System.out.println("总金额为："+sum*k);   
        }
    
}