数据结构--顺序栈java实现

傷城~ 2022-07-16 02:10 242阅读 0赞

# 数据结构--顺序栈java实现    #

1.顺序栈的简单实现，java

（1）接口

public interface IStack {
    	public void clear();	//清空栈
    	public boolean isEmpty();		//栈的判空
    	public Object peek();		//查询栈顶元素
    	public int length();		//栈的长度
    	public void push(Object x) throws Exception;	//元素入栈
    	public Object pop();	//栈顶元素出栈
    }

（2）实现顺序栈

//顺序栈的实现，java
    public class SqStack implements IStack{
    	private Object[] stackElem;		//对象数组
    	private int top; //top始终指向栈顶元素的上一个元素，栈为空时top=0
    	
    	//栈的构造函数，构造一个空间为maxSize的栈
    	public SqStack(int maxSize){
    		top = 0;
    		stackElem = new Object[maxSize];
    	}
    	//置空顺序栈
    	@Override
    	public void clear() {
    		// TODO Auto-generated method stub
    		top = 0;
    	}
    	//判断是否为空栈
    	@Override
    	public boolean isEmpty() {
    		// TODO Auto-generated method stub
    		return top == 0;
    	}
    	//取栈顶元素
    	@Override
    	public Object peek() {
    		// TODO Auto-generated method stub
    		if(isEmpty()){
    			return null;
    		}else{
    			return stackElem[top-1];
    		}
    	}
    	//栈中元素的个数
    	@Override
    	public int length() {
    		// TODO Auto-generated method stub
    		return top;
    	}
    	//元素入栈
    	@Override
    	public void push(Object x) throws Exception {
    		// TODO Auto-generated method stub
    		if(top == stackElem.length){
    			throw new Exception("栈满");
    		}
    		stackElem[top] = x;
    		top++;
    	}
    	//元素出栈
    	@Override
    	public Object pop() {
    		// TODO Auto-generated method stub
    		if(isEmpty()){
    			return null;
    		}
    		top--;
    		return stackElem[top];
    	}
    /*
     * 测试用，忽略
     */
    //	public static void main(String[] args) throws Exception{
    //		SqStack mystack = new SqStack(5);
    //		mystack.push(1);
    //		mystack.push(2);
    //		mystack.push(3);
    //		mystack.push(4);
    //		mystack.push(5);
    //		System.out.println(mystack.length());
    //		System.out.println(mystack.isEmpty());
    //		System.out.println(mystack.peek());
    //		for(int i=0;i<5;i++){
    //			System.out.println(mystack.pop());
    //		}
    //		System.out.println(mystack.isEmpty());
    //		System.out.println(mystack.length());
    //	}
    }