堆栈面试例题

题目：

实现一个栈操作，将1~12月的英文单词压入栈中，然后再将其取出，使用Java代码实现。

 

答案：

package book;

import java.util.*;

public class JiOu {
	static String[] months = { "January", "February", "March",
        "April", "May", "June", "July", "August", "September",
			"October", "November", "December" };

	public static void main(String[] args) {
		Stack stack = new Stack();
		for (int i = 0; i < months.length; i++) {
			stack.push(months[i] + "  ");
		}
		System.out.println("stack=" + stack);
		stack.addElement("The last line");
		System.out.println("element 5 = " + stack.elementAt(5));
		System.out.println("popping elements:");
		while (!stack.empty()) {
			System.out.println(stack.pop());
		}
	}
}

运行结果：

stack=[January  , February  , March  , April  , May  , June  , July  , August  , September  , October  , November  , December  ]
element 5 = June  
popping elements:
The last line
December  
November  
October  
September  
August  
July  
June  
May  
April  
March  
February  
January  

 

扩展：

本题也可以通过队列来实现，代码如下:

package book;

import java.util.*;

public class JiOu {
	static String[] months = { "January", "February", "March", 
      "April", "May", "June", "July", "August", "September",
			"October", "November", "December" };

	public static void main(String[] args) {
		Vector vq = new Vector();
		for (int i = 0; i < months.length; i++) {
			vq.addElement(months[i] + "  ");
		}
		if (vq.isEmpty()) {
			System.out.println("空");
		}

		while (!vq.isEmpty()) {
			System.out.println(vq.firstElement());
			vq.removeElement(vq.firstElement());
		}
		vq.clear();
	}
}

 

运行结果：