JAVA数据结构之栈的实现

1、栈的实现类Stack的代码如下所示：

public class Stack {
	private Object[] array;//存放栈元素的数组
	private int capacity;//栈的容量
	private int top;//栈顶元素的索引
	
	public Stack(){
		
	}
	
	public Stack(int capacity){
		create(capacity);
	}
	
	//创建栈
	public void create(int capacity){
		array = new Object[capacity];
		this.capacity = capacity;
		this.top = 0;
	}
	
	//入栈
	public boolean push(Object data){
		boolean ret = (array != null) && (data != null) && (top < capacity);
		
		if(ret){
			array[top++] = data;
		}
		
		return ret;
	}
	
	//出栈
	public Object pop(){
		Object ret = null;
			
		if((array != null) && (top > 0) && (top <= capacity)){
			ret = array[--top];
		}
			
		return ret;
	}
	
	//栈的容量
	public int getCapacity(){
			return capacity;
	}
	
	//栈中的元素个数
	public int getCount(){
		return top;
	}
	
	//栈是否为空
	public boolean isEmpty(){
		return top == 0;
	}
}





 2、测试类Test的实现代码如下所示：
public class Test {

	public static void main(String[] args) {
		Stack stack = new Stack();
		
		stack.create(5);
		stack.push("元素1");
		stack.push("元素2");
		stack.push("元素3");
		
		System.out.println("栈的容量："+stack.getCapacity());
		System.out.println("元素个数："+stack.getCount());
		System.out.println("栈是否为空？"+stack.isEmpty());
		
		System.out.println("\n栈中的所有元素:");
		while(!stack.isEmpty()){
			System.out.print(stack.pop()+" ");
		}
	}
}