线性结构之一:栈
栈是一个先入后出的有序列表
栈的元素不能从列表中间增加和删除,
只能从顶端增删数据,称为栈顶;
底端为固定的一端不进行元素的增删,称为栈底

数组模拟栈

栈类:
属性:栈大小/数组模拟栈/栈顶(top = -1)
方法:
判断栈是否满:用栈顶的标记值top == 栈大小 - 1
判断栈是否空:top ==  - 1
入栈
出栈
显示栈所有数据
显示栈顶元素
构造器:初始化数组大小

package stack;public class MyStackInt {private int maxSize;// 栈大小private int[] stack;// 数组栈private int top = -1;// 栈顶public MyStackInt() {super();// TODO Auto-generated constructor stub}public MyStackInt(int maxSize) {super();this.maxSize = maxSize;this.stack = new int[maxSize];}// 判断栈是否满public boolean isFull() {// return stack.length == maxSize;return top == maxSize - 1;}// 判断栈是否已经空public boolean isEmpty() {// return stack.length == 0;return top == -1;}// 入栈public void push(int i) {// 先判断栈是否已满if (isFull()) {System.out.println("栈已经满了!");return;}top++;stack[top] = i;System.out.println("添加成功!");}// 出栈public int pop() {if (isEmpty()) {// System.out.println("栈已经空了");// return -1;throw new RuntimeException("栈已经空了");}int temp = stack[top];top--;System.out.println("取值成功! " + temp);return temp;}//显示栈顶元素不是取出元素public int peek() {if (isEmpty()) {throw new RuntimeException("栈已经空了");}return stack[top];}// 遍历栈的元素(不是取值),先进后出public void list() {if (isEmpty()) {System.out.println("栈已经空了");return;}for (int i = top; i >= 0; i--) {System.out.println(stack[i]);}}}

测试类:

		MyStackInt stack = new MyStackInt(5);stack.push(1);stack.push(2);stack.push(3);stack.push(4);System.out.println("栈顶元素" + stack.peek());stack.list();stack.pop();System.out.println("栈顶元素" + stack.peek());stack.list();