用数组实现堆栈和队列

1. package com.sms;
3. /**
4.  * 
5.  * @author Administrator
6.  *
7.  */
8. public class Stack {
9.    public static  int MAX_SIZE=10;
10.    private Object[] stack = new Object[MAX_SIZE];
11.    int currentPos=-1;
12.    public void push(Object obj) throws Exception
13.    {
14.        print("push:"+obj);
15.        if(currentPos<MAX_SIZE-1)
16.        {
17.            stack[++currentPos]=obj;
18.        }
19.        else
20.        {
21.            stack= appendArray(stack);
22.            stack[++currentPos]=obj;
23.            MAX_SIZE=stack.length;
24.        }
25.     }
26.    
27.    private Object[] appendArray(Object[] stack2) {
28.     // TODO Auto-generated method stub
29.     Object[] stack3 = new Object[stack2.length+MAX_SIZE];
30.     for(int i=0;i<stack2.length;i++)
31.     {
32.         stack3[i]=stack2[i];
33.     }
34.     return stack3;
35. }
37. public Object pop() throws Exception
38.    {
39.        Object popobj=null;
40.        if(currentPos>-1)
41.        {
42.            popobj=stack[currentPos];
43.            print("pop:"+popobj);
44.            stack[currentPos--]=null;
45.            
46.         }
47.        return popobj;
48.    }
50. public int getSize()
51. {
52.     return currentPos+1;
53. }
54.    
55.    public static void main(String args[]) 
56.    {
57.        Stack stack = new Stack();
58.        try
59.        {
60.            stack.push("1");
61.            stack.push("2");
62.            stack.push("3");
63.            stack.push("4");
64.            stack.pop();
65.            stack.pop();
66.            stack.push("5");
67.            stack.push("6");
68.            stack.push("1");
69.            stack.push("2");
70.            stack.pop();
71.            stack.pop();
72.            stack.pop();
73.            stack.pop();
74.            stack.pop();
75.            stack.pop();
76.            stack.pop();
77.            stack.push("3");
78.            stack.push("4");
79.            stack.push("5");
80.            stack.pop();
81.            stack.push("6");
82.            
83.            for(int i=0,j=stack.getSize();i<j;i++)
84.            {
85.               
86.                System.out.println("obj:"+(String)stack.pop());
87.            }
88.        }
89.        catch(Exception e)
90.        {
91.            e.printStackTrace();
92.        }
93.        
94.        
95.    }
96.    private void print(String msg)
97.    {
98.        System.out.println(msg);
99.    }
100. }
101. 1. package com.sms;
     3. /**
     4.  * 
     5.  * @author Administrator
     6.  *
     7.  */
     8. public class Queue {
     9. private static int MAX_SIZE=10;
     10. private Object[] queue = new Object[MAX_SIZE];
     11. int currentPos=-1;
     12. int head=-1;
     14. public void push(Object obj)
     15. {
     16.     try
     17.     {
     18.         if(currentPos<MAX_SIZE-1)
     19.         {
     20.             queue[++currentPos]=obj;
     21.             if(currentPos==0) head=0;
     22.         }
     23.         else
     24.         {
     25.             if(head==0)
     26.             {
     27.                 queue=appendQueue(queue,head,MAX_SIZE);
     28.                 MAX_SIZE=MAX_SIZE+MAX_SIZE;
     29.                 queue[++currentPos]=obj;
     30.             }
     31.             else
     32.             {
     33.                 queue=appendQueue(queue,head,0);
     34.                 
     35.                 currentPos=currentPos-head;
     36.                 queue[++currentPos]=obj;
     37.                 head=0;
     38.                 
     39.             }
     40.             
     41.             
     42.         }
     43.     }
     44.     catch(Exception e)
     45.     {
     46.         e.printStackTrace();
     47.     }
     48. }
     50. public Object pop()
     51. {
     52.     Object popObj=null;
     53.     try
     54.     {
     55.         if(currentPos==head && head!=-1)
     56.         {
     57.             popObj=queue[head];
     58.             queue[head]=null;
     59.             currentPos=-1;
     60.             head=-1;
     61.         }
     62.         else if(head==-1) 
     63.         {
     64.             
     65.         }
     66.         else
     67.         {
     68.             popObj=queue[head];
     69.             queue[head++]=null;
     70.         }
     71.         
     72.     }
     73.     catch(Exception e)
     74.     {
     75.         e.printStackTrace();
     76.     }
     77.     return popObj;
     78.     
     79. }
     81. public int getSize()
     82. {
     83.     if(currentPos==-1) return 0;
     84.     else 
     85.         return currentPos-head+1;
     86. }
     87. private Object[] appendQueue(Object[] queue2, int pos, int appendSize) {
     88.     // TODO Auto-generated method stub
     89.     Object[] newQueue = new Object[MAX_SIZE+appendSize];
     90.     for(int j=0,i=pos;i<MAX_SIZE;i++)
     91.     {
     92.         newQueue[j++]=queue2[i];
     93.     }
     94.     return newQueue;
     95. }
     97. public static void main(String args[]) 
     98. {
     99.        Queue stack = new Queue();
     100.        try
     101.        {
     102.            stack.push("1");
     103.            stack.push("2");
     104.            stack.push("3");
     105.            stack.push("4");
     106.            stack.pop();
     107.            stack.pop();
     108.            stack.push("5");
     109.            stack.push("6");
     110.            stack.push("1");
     111.            stack.push("2");
     112.            stack.push("5");
     113.            stack.push("6");
     114.            stack.push("1");
     115.            stack.push("2");
     116.            stack.pop();
     117.            stack.pop();
     118.            stack.pop();
     119.            stack.pop();
     120.            stack.pop();
     121.            stack.pop();
     122.            stack.pop();
     123.            stack.push("3");
     124.            stack.push("4");
     125.            stack.push("5");
     126.            stack.pop();
     127.            stack.push("6");
     128.            
     129.            for(int i=0,j=stack.getSize();i<j;i++)
     130.            {
     131.               
     132.                System.out.println("obj:"+(String)stack.pop());
     133.            }
     134.        }
     135.        catch(Exception e)
     136.        {
     137.            e.printStackTrace();
     138.        }
     139.        
     140.        
     141. }
     142. private void print(String msg)
     143. {
     144.        System.out.println(msg);
     145. }
     146. }