算法－第四版－练习1.3.2解答

给定以下输入，java Stack的输出是什么？

it was - the best - of times - - - it was - the - -

Stack：

/**
 * Description : 
 * Author      : mn@furzoom.com
 * Date        : Sep 27, 2016 5:07:34 PM
 * Copyright (c) 2013-2016, http://furzoom.com All Rights Reserved.
 */
package com.furzoom.lab.algs.ch103;

import java.util.Iterator;

import edu.princeton.cs.algs4.StdIn;
import edu.princeton.cs.algs4.StdOut;

/**
 * ClassName    : Stack <br>
 * Function     : TODO ADD FUNCTION. <br>
 * date         : Sep 27, 2016 5:07:34 PM <br>
 * 
 * @version 
 */
public class Stack<Item> implements Iterable<Item>
{
    private Node first;
    private int n;
    private class Node
    {
        Item item;
        Node next;
    }
        
    public boolean isEmpty() 
    {
        return first == null;
    }
    
    public int size()
    {
        return n;
    }
    
    public void push(Item item)
    {
        Node oldfirst = first;
        first = new Node();
        first.item = item;
        first.next = oldfirst;
        n++;
    }
    
    public Item pop()
    {
        Item item = first.item;
        first = first.next;
        n--;
        return item;
    }
       
    @Override
    public Iterator<Item> iterator()
    {
        return new ReverseArrayIterator();
    }
    
    private class ReverseArrayIterator implements Iterator<Item>
    {
        private Node p = first;
        @Override
        public boolean hasNext()
        {
            return p != null;
        }

       @Override
        public Item next()
        {
           Item item = p.item;
           p = p.next;
           return item;
        }
        
    }

    public static void main(String[] args)
    {
        Stack<String> s;
        s = new Stack<String>();
        while (!StdIn.isEmpty())
        {
            String item = StdIn.readString();
            if (!item.equals("-"))
                s.push(item);
            else if (!s.isEmpty())
                StdOut.print(s.pop() + " ");
        }
        StdOut.println("(" + s.size() + " left on stack)");
    }
}

E10302.txt

it was - the best - of times - - - it was - the - -

结果如下：

>java -cp ".;../lib/algs4.jar" com
.furzoom.lab.algs.ch103.Stack < com/furzoom/lab/algs/ch103/E10302.txt
was best times of the was the it (1 left on stack)

算法－第四版－1.3 背包、队列和栈－习题索引汇总

算法－第四版习题索引汇总