答答租车系统（代码还能更简洁更容易吗？还能分别计算每辆车的租赁天数）

做项目要的就是最少的代码实现最多的功能，而且用最简单的知识来实现它。
-------玄鉴
//父类----车，省略了，get/set方法。
public class Che {

private String name;
private int daymoney;
private int day;
public void  show() {
System.out.print("\t"+this.name+
        "\t"+this.daymoney+"元/天\t");
}}

//子类——客车.省略了，get/set方法。
public class Car extends Che {

private int personNum;

Car(String name, int daymoney,int personNum) {
    super(name, daymoney);
    this.personNum=personNum;
}

@Override
public void show() {

    //super.show();

    System.out.print("\t"+this.getName()+
            "\t"+this.getDaymoney()+"元/天\t");
    System.out.print("载人："+personNum+"人");

}

————————————————————
//子类——货车 省略了，get/set方法。

public class Bus extends Che {

private int cargoNum;

Bus(String name, int daymoney,int cargoNum) {
    super(name, daymoney);

    this.cargoNum=cargoNum;
}

@Override
public void show() {

    super.show();
    System.out.print("载货："+cargoNum+"吨");
}

}

//子类——载货载人两用车。 省略了，get/set方法。
public class Pika extends Che {

private int personNum;
private int cargoNum;

Pika(String name, int daymoney,int personNum,int cargoNum) {
    super(name, daymoney);

    this.personNum=personNum;
    this.cargoNum=cargoNum;
}

@Override
public void show() {

    super.show();

    System.out.print("载货："+cargoNum+"吨"+
            "载人："+personNum+"人");
}

————————————————————
//流程测试类

import java.util.Scanner;

public class Liucheng {

public static void main(String[] args) {
    System.out.println("欢迎使用租车系统");
    System.out.println("您是否要租车（1.是  2.否）");
    Scanner in = new Scanner(System.in);

    Che[] ches = { new Car("奥迪A4", 500, 4), new Car("马自达", 400, 4),
            new Pika("皮卡雪6", 450, 4, 2), new Bus("金龙", 800, 20),
            new Bus("松花江", 400, 4), new Bus("依维柯", 1000, 20) };
    if (in.nextInt() == 1) {
        System.out.println("序号" + "\t汽车名称" + "\t租金" + "\t容量");
        for (int i = 0; i < ches.length; i++) {
            System.out.print(i);
            ches[i].show();
            System.out.println("");
        }
    }else{
                    System.out.println("程序退出。");
        return;
        }

    System.out.println("请问你要租车的数量：");
    int a = in.nextInt();

    int sum = 0;
    int d = 0;
    for (int i = 0; i < a; i++) {
        System.out.println("请问你租赁的第" + (i + 1) + "辆车的序号是：");

        int b = in.nextInt();

if (b>=0&&b<6) {
System.out.println("请问你要租的天数：");
int c = in.nextInt();
ches[b].setDay(c);
d = ches[b].getDaymoney() * ches[b].getDay();

        sum = sum + d;
        System.out.println("第" + (i + 1) + "辆车" + ches[b].getName()
                + "的价钱为：" + d);
    }else {
            System.out.println("输入有误，请重新输入");
            continue;

}
}
System.out.println("总价钱为：" + sum);
}
}