顺序栈的实现

 1 package com.yeyan.seqstack;
 2 /**
 3  * 顺序栈的接口
 4  * @author yeyan
 5  * @date   2014-12-8
 6  * API:
 7  * push(Object obj)              入栈
 8  * pop()                         出栈
 9  * getTop()                      获取栈顶元素
10  * isEmpty()                     判断栈是否为空
11  */
12 public interface Stack {
13     //入栈
14     public void push(Object obj) throws Exception;
15     //出栈
16     public Object pop() throws Exception;
17     //获取栈顶元素
18     public Object getTop() throws Exception;
19     //判断栈是否为空
20     public boolean isEmpty() throws Exception;
21 }

 1 package com.yeyan.seqstack;
 2 /**
 3  * 顺序栈实现类
 4  * @author yeyan
 5  * @date   2014-12-08
 6  *
 7  */
 8 public class SeqStack implements Stack {
 9     private Object[] stack;                     //对象数组
10     private final int defaultSize = 10;         //默认长度
11     private int top;                            //栈顶位置
12     private int maxSize;                        //最大长度
13 
14     /**
15      * 不带参的构造函数
16      */
17     public SeqStack(){
18         this.maxSize = defaultSize;
19         top = 0;
20         stack = new Object[defaultSize];
21     }
22     /**
23      * 带参构造函数
24      */
25     public SeqStack(int size){
26         this.maxSize = size;
27         top = 0;
28         stack = new Object[size];
29     }
30     
31     /**
32      * 入栈的实现
33      */
34     @Override
35     public void push(Object obj) throws Exception {
36         //先判断栈是否已满
37         if(top == maxSize) {
38             throw new Exception("堆栈已满！");
39         } else {
40             stack[top] = obj;
41             top ++;
42         }
43     }
44 
45     /**
46      * 出栈的实现
47      */
48     @Override
49     public Object pop() throws Exception {
50         if(isEmpty()) {
51             throw new Exception("栈为空！");
52         }
53         top --;
54         return stack[top];
55     }
56 
57     /**
58      * 获取栈顶元素
59      */
60     @Override
61     public Object getTop() throws Exception {
62         if(isEmpty()) {
63             throw new Exception("栈为空!");
64         }
65         return stack[top-1];
66     }
67 
68     /**
69      * 判断栈是否为空
70      */
71     @Override
72     public boolean isEmpty() throws Exception {
73         return top == 0;
74     }
75 
76 }

 1 package com.yeyan.seqstack;
 2 /**
 3  * 顺序栈测试类
 4  * @author yeyan
 5  * @date   2014-12-08
 6  *
 7  */
 8 public class Test {
 9 
10     public static void main(String[] args) {
11         SeqStack seqStack = new SeqStack(20);
12         //入栈测试(用10个元素模拟)
13         System.out.println("请输入10个整数：");
14         for(int i = 0; i < 10; i ++) {
15             try {
16                 seqStack.push(i);
17             } catch (Exception e) {
18                 e.printStackTrace();
19             }
20         }
21         //出栈测试
22         for(int i = 0; i < 10; i ++) {
23             try {
24                 Object obj = seqStack.pop();
25                 System.out.println(Integer.parseInt(obj.toString()));
26             } catch (Exception e) {
27                 e.printStackTrace();
28             }
29         }
30     }
31 
32 }