基於陣列實現

package com.ma.stack;
 
/**
 * @author sunfch
 *此棧實現基於陣列，初始棧時已經設定棧大小
 */
public class MyArrayStack {
	private int size;
	private int top = -1;
	private int[] arr;
 
	MyArrayStack(){
		arr =new int[3]; //預設棧大小為3
	}
	MyArrayStack(int size) {
		if(size > 0){
			this.size = size;
			arr = new int[size];
		}
		else throw new RuntimeException("陣列長度值不正確");
	}
	//==============================================================================
	//入棧
	public void push(int data){
		if(top >= size-1){
			System.out.println("棧已滿");
			return;
		}
		arr[++top] = data;
	}
	//==============================================================================
	//出棧
	public int pop(){
		if(top < 0){
			throw new RuntimeException("棧為空");
		}
		else{
			int temp = arr[top];
			arr[top] = 0;
			top--;
			return temp;
		}
	}
	
	//檢視棧頂元素但不出棧
	public int peek(){
		if(top < 0){
			throw new RuntimeException("棧為空");
		}
		else{
			return arr[top];
		}
	}
	//==============================================================================
	
	public boolean isEmpty(){
		return top == -1;
	}
 
	//==============================================================================
 
	public static void main(String[] args) {
		MyArrayStack stack = new MyArrayStack(3);//初始棧大小為3
		stack.push(2);
		stack.push(5);
		stack.push(10);
		//stack.push(11);
		System.out.println(stack.pop());
		System.out.println(stack.pop());
		System.out.println(stack.pop());
		//System.out.println(stack.pop());
//		System.out.println(stack.peek());
//		System.out.println(stack.peek());
		System.out.println(stack.isEmpty());
		
	}
 
}
 

基於陣列實現：

package com.ma.stack;
 
/**
 * @author sunfch
 * 此棧實現基於連結串列，初始棧時未設定棧大小（棧大小可變）
 *此棧是將新元素插到連結串列頭部（連結串列頭部是棧頂）
 */
public class MyLinkStack {
	private Node top;//記錄棧頂元素
	private int size = 0;//記錄棧大小
 
	
	public MyLinkStack() {
		top = null;
	}
	class Node{
		public int data; //記錄資料
		public Node next;
		Node(int data){
			this.data = data;
		}
	}
	
//=============================================================================================	
	//入棧
	public void push(int data){
		Node newNode = new Node(data);
		if(top == null){
			top =newNode;
			
			
		}
		else{
			newNode.next = top;//將新元素插到連結串列頭部
			top = newNode;
		}
		size++;
	}
//=============================================================================================	
	//出棧
	public Integer pop(){
		if(top == null) throw new RuntimeException("棧為空");
		else{
			int val = top.data;
			top = top.next;
			size--;
			return val;
		}
		
	}
	//檢視棧頂元素但不出棧
	public Integer peek(){
		if(top == null) throw new RuntimeException("棧為空");
		else{
			return top.data;
		}
		
	}
//=============================================================================================	
	
	public boolean isEmpty(){
        return top == null;
    }
	
	public int getSize(){
		return size;
	}
	
//=============================================================================================	
 
	public static void main(String[] args) {
		MyLinkStack my = new MyLinkStack();
		my.push(4);
		my.push(5);
		my.push(6);
		System.out.println("當前size："+my.getSize());
		System.out.println(my.isEmpty());
		System.out.println(my.pop());
		System.out.println("當前size："+my.getSize());
		System.out.println(my.pop());
		System.out.println(my.pop());
		System.out.println(my.isEmpty());
		//System.out.println(my.pop());
	}
}