數據結構03.1->Stack棧的模擬(數組)

package aa.bb.cc.demo;

import java.util.Stack;

/**
 * Stack的模擬(數組)
 * @author 州偉
 * @note 用數組模擬一個棧，注意數組是沒有變化的，不會刪除數組節點，主要是利用top值的變化來實現stack
 */
public class MyStack {
	//Stack底層是一個數組(當然也可以list vector等，主要看是否要線程安全？？？？)
	private long[] arr;
	private int top;	//Stack頂
	
	//默認構造方法
	public MyStack(){
		arr = new long[10];
		top = -1;
		
	}
	
	//帶參數的構造方法
	public MyStack(int maxSize){
		arr = new long[maxSize];
		top = -1;
	}
	
	//添加數據???
	public void push(int value){
		/**
		 * 這樣理解
		 * arr[top=top+1] = value;
		 */
		arr[++top] = value;	
	}
	
	//移除一個數據???
	public long pop(){
		/**
		 * 沒有刪除的過程??????
		 */
		return arr[top--];
	}
	
	//查看數據???
	public long peek(){
		return arr[top];
	}
	
	//判斷是否爲空
	public boolean isEmpty(){
		return top == -1;
	}
	
	//判斷是否滿了
	public boolean isFull(){
		return top == arr.length -1;
	}
	
	
	/**
	 * main
	 * @param args
	 */
	public static void main(String[] args) {
		MyStack ms = new MyStack(4);
		ms.push(23);
		ms.push(1);
		ms.push(90);
		ms.push(12);
		System.out.println(ms.isEmpty());
		System.out.println(ms.isFull());
		
		System.out.println(ms.peek());
		System.out.println(ms.peek());
		System.out.println();
		
		//先進後出，先出後進
		while(!ms.isEmpty()){
			System.out.println(ms.pop());
		}
		
		System.out.println(ms.isEmpty());
		System.out.println(ms.isFull());
		
		System.out.println("--------------自己模擬的stack與JDK中的Stack對比----------------");
		
		//JDK中的Stack
		Stack stack = new Stack();
		stack.push(23);
		stack.push(1);
		stack.push(90);
		stack.push(12);
		System.out.println(stack.isEmpty());
		
		System.out.println(stack.peek());
		System.out.println(stack.peek());
		System.out.println();
		
		//先進後出，先出後進
		while(!stack.isEmpty()){
			System.out.println(stack.pop());
		}
		
		System.out.println(stack.isEmpty());

	}

}