Java栈实现

1. 定义栈所有方法接口:
package com.dataStructure.stack;

/**
* 类功能描述:
*
* @version 1.0.0
* @auther Create by Barry
* @date Create on 2018/3/12.
* @history
*/
public interface Stack {
public boolean push(Object element);

public Object pop();

public Object peek();

public int elementCount();

public boolean isEmpty();

public void showElements();
}

2. 基于数组的栈实现

package com.dataStructure.stack;

/**
* 类功能描述:
*
* @version 1.0.0
* @auther Create by Barry
* @date Create on 2018/3/12.
* @history
*/
public class ArrayStack implements Stack{
private int maxSize;
private Object data[];
private int top = -1;

public ArrayStack(int maxSize){
data = new Object[maxSize];
this.maxSize = maxSize;
}

@Override
public boolean push(Object element){
if(top == maxSize-1){
return false;
}
data[++top] = element;
return true;
}

@Override
public Object pop(){
if(this.isEmpty()){
return -1;
}
Object returnData = data[top];
top--;
return returnData;
}

@Override
public Object peek(){
if(this.isEmpty()){
return -1;
}
return data[top];
}

@Override
public int elementCount(){
return top+1;
}

@Override
public boolean isEmpty(){
if(top == -1){
return true;
}
return false;
}

@Override
public void showElements(){
System.out.println("--------Show all element start--------");
for(int i=top; i>=0; i--){
System.out.println(data[i]);
}
System.out.println("--------Show all element end--------");
}

public static void main(String[] args){
Stack stack = new ArrayStack(11);

/*System.out.println("=============================test 1 start--------------");
stack.push(1);
stack.showElements();
System.out.println(stack.elementCount());
System.out.println("=============================test 1 end--------------");
System.out.println("=============================test 2 start--------------");
stack.push(2);
stack.showElements();
System.out.println(stack.elementCount());
System.out.println("=============================test 2 end--------------");
System.out.println("=============================test 3 start--------------");
stack.pop();
stack.showElements();
System.out.println(stack.elementCount());
System.out.println("=============================test 3 end--------------");*/
/*System.out.println("=============================test 4 start--------------");
for(int i=1; i<=12; i++ ){
stack.push(i);
}
stack.showElements();
System.out.println(stack.elementCount());
System.out.println("=============================test 4 end--------------");*/

String str = "1234321";
System.out.println(ArrayStack.isSysmetryStr(str));
}

/**
* 用栈判断字符串是否为对称串,
* 即从左到右和从右到左读取是一样的
* 1234321为对称串
* @param str
* @return
*/
public static boolean isSysmetryStr(String str){
if(str == null || str.length() == 0){
return true;
}

Stack stack = new ArrayStack(str.length());
for(int i=0; i < str.length(); i++){
stack.push((int)str.charAt(i));
}

for(int i=0; i < str.length(); i++){
Object data = stack.pop();
if((int)data == (int)str.charAt(i)){
return false;
}
}

return true;
}
}

3. 基于链表的栈实现
package com.dataStructure.stack;

/**
* 类功能描述:
*
* @version 1.0.0
* @auther Create by Barry
* @date Create on 2018/3/12.
* @history
*/
public class LinkedStack implements Stack{
private Node header;
private int elementCount = 0;
private int maxSize;

public LinkedStack(int maxSize){
this.maxSize = maxSize;
}

@Override
public boolean push(Object data) {
if(elementCount == maxSize){
throw new RuntimeException("Stack is Full");
}
header = new Node(data, header);
elementCount++;
return true;
}

@Override
public Object pop() {
if(isEmpty()){
throw new RuntimeException("Stack is empty");
}
Object returnData = header.data;
header = header.next;
elementCount--;
return returnData;
}

@Override
public Object peek() {
return header.data;
}

@Override
public int elementCount() {
return elementCount;
}

@Override
public boolean isEmpty() {
return (elementCount == 0);
}

@Override
public void showElements() {
while (header != null){
System.out.println(header.data);
header = header.next;
}
}

class Node{
private Object data;
private Node next;

public Node(Object data){
this(data, null);
}

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

public static void main(String[] args) {
Stack stack = new ArrayStack(5);
for(int i=1; i<=5; i++){
stack.push(i);
}
stack.pop();
stack.showElements();
}

}
posted @ 2018-03-12 23:40  BarryW  阅读(873)  评论(0编辑  收藏  举报