java拾遗录4
一、用数组实现栈操作
废话不说，直接上代码
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package stack;/** *@作者 qy *@时间版本 版本1 下午08:49:07 2011-8-30 */public class StackTestByArray{private Object[] array;private int top;public StackTestByArray(int size){array = new Object[size];top = -1;}//判断栈是否为空public boolean isEmpty(){return top == -1;}//判断栈是否满public boolean isFull(){return size() == array.length;}//返回当前栈的大小public int size(){return top+1;}//弹栈public Object pop(){if (isEmpty()){System.out.println("栈为空");return null;}Object temp = array[top];array[top] = null;top -= 1;return temp;}public void push(Object newValue){if (newValue == null){System.out.println("入栈数据为null");return;}if (isFull()){System.out.println("栈满");return;}top++;array[top] = newValue;}//取栈头元素public Object peek(){if (isEmpty()){System.out.println("栈为空");return null;}return array[top];}}?这是使用数组实现的栈，很简单。
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下面是链表实现：（Node类看我前面的文章即可）
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package stack;import array.Node;/** *@作者 qy *@时间版本 版本1 下午09:15:56 2011-8-30 */public class StackTestByNode{private Node top ;private int count;public StackTestByNode(){top = null;count = 0;}//是否栈满public boolean isFull(){//这里我们用的链表 姑且没有满的状态 内存爆了再说return false;}//是否栈空public boolean isEmpty(){return count == 0;}//大小public int size(){return count;}//入栈public void push(Object value){if (value == null){System.out.println("插入数据为null");return ;}count++;Node n = new Node(value, top);top = n;}//出栈public Object pop(){if (isEmpty()){System.out.println("栈空");return null;}count--;Object value = top.value;top = top.next;return value;}//取栈顶元素public Object peek(){if (isEmpty()){System.out.println("栈空");return null;}return top.value;}}??也是很简单，就不多说了，大家看看就好，不要出声.........