数据结构之栈的实现

一、以数组为内核的栈的实现：

package data.struct.algorithm;

class Stackx {
    private int maxSize;
    private int[] stackArray;
    private int top;

    //自己的错误出现在这个地方，错误写法：maxSize=this.maxSize;
    public Stackx(int maxSize) {
        this.maxSize = maxSIze;
        stackArray = new int[maxSize];
        top = -1;
    }

    public void push(int j) {
        stackArray[++top] = j;
    }

    public int pop() {
    return stackArray[top--];
    }

    public int peek() {
        return stackArray[top];
    }

    public boolean isEmpty() {
        return top==-1;
    }

    public boolean isFull() {
        return top==maxSize-1;
    }
}

public class StackApp {

    /**
     * @param args
     */
    public static void main(String[] args) {

        Stackx theStackx = new Stackx(10);
        theStackx.push(20);
        theStackx.push(40);
        theStackx.push(60);
        theStackx.push(80);
        theStackx.push(1);
        theStackx.push(67);
        theStackx.push(78);
        theStackx.push(23);
        System.out.println(theStackx.peek());
        while (!theStackx.isEmpty()) {
            System.out.print(theStackx.pop()+" ");
        }
        System.out.println();
    }

}

 二、用链表来实现栈

package data.struct.algorithm;

/*
 * 用链表实现栈，用的就是insertFirst()和deleteFirst方法，即插入和删除结点都在链表头进行
 */
class Node {
    public int data;
    public Node next;

    public Node(int data, Node next) {
        this.data = data;
        this.next = next;
    }
}

class LinkList {
    private Node head;

    public LinkList() {
        head = null;
    }

    public void insertFirst(int data) {
        Node newNode = new Node(data, null);
        newNode.next = head;
        head = newNode;
    }

    public Node deleteFirst() {
        if (head == null) {
            return null;
        }
        Node tempNode = head;
        head = head.next;
        return tempNode;
    }

    public boolean isEmpty() {
        return head == null;
    }
}

class LinkStack {
    private LinkList theStack;

    public LinkStack() {
        theStack = new LinkList();
    }

    public void push(int data) {
        theStack.insertFirst(data);
    }

    public void pop() {
        System.out.println(theStack.deleteFirst().data);
    }

    public boolean isEmpty() {
        return theStack.isEmpty();
    }
}

public class LinkListStackTest {

    /**
     * @param args
     */
    public static void main(String[] args) {

        LinkStack theStack = new LinkStack();
        theStack.push(10);
        theStack.push(20);
        theStack.push(30);
        theStack.push(40);
        theStack.push(50);
        while (!theStack.isEmpty()) {
            theStack.pop();
        }
    }

}