/*第一题:
编写程序,使用一维数组,模拟栈数据结构。
要求:
1、这个栈可以存储java中的任何引用类型的数据。
2、在栈中提供push方法模拟压栈。(栈满了,要有提示信息。)
3、在栈中提供pop方法模拟弹栈。(栈空了,也有有提示信息。)
4、编写测试程序,new栈对象,调用push pop方法来模拟压栈弹栈的动作。
*/
package com.bjpowernode.javase.day23homework;
public class Homework1 {
public static void main(String[] args) {
MyStack myStack = new MyStack();
//压栈
try {
myStack.push(new A());
myStack.push(new A());
myStack.push(new A());
} catch (StackException e) {
e.printStackTrace();
}
try {
myStack.pop();
myStack.pop();
myStack.pop();
} catch (StackException e) {
e.printStackTrace();
}
}
}
class A{}
class B{}
class C{}
class MyStack{
//定义object数组,提供空间压栈弹栈
private Object[] objects;
//栈帧,永远指向栈顶元素,初始情况object数组没有元素,栈帧指向-1
private int index = -1;
//pop
public Object pop() throws StackException {
//判断栈空否
if (index < 0){
throw new StackException("栈已空,弹栈失败!");
}else{
//返回当前元素后,栈帧所指元素进行减一操作
System.out.println("弹栈成功," + objects[index]);
return objects[index--];
}
}
//push
public void push(Object obj)throws StackException{
if (index >= objects.length-1){
throw new StackException("栈已满,弹栈失败!");
}else{
//压栈,将引用类型数据压入栈中
this.objects[++index] = obj;
System.out.println("压栈成功," + obj);
}
}
//constructor
public MyStack() {
//初始默认栈空间为2
this(new Object[2]);
}
public MyStack(Object[] objects) {
this.objects = objects;
}
//setter and getter
public Object[] getObjects() {
return objects;
}
public void setObjects(Object[] objects) {
this.objects = objects;
}
public int getIndex() {
return index;
}
public void setIndex(int index) {
this.index = index;
}
}
package com.bjpowernode.javase.day23homework;
public class StackException extends Exception{
public StackException() {
}
public StackException(String message) {
super(message);
}
}