算法(第四版)学习笔记之java实现栈和队列(链表实现)

下压堆栈(链表实现)：

import java.util.Iterator;

public class LinkedStack<Item> implements Iterable<Item>
{

	public class Node
	{
		Item item;
		Node next;
	}
	private Node frist;
	private int N = 0;

	public boolean isEmpty()
	{
		return N == 0;
	}

	public int size()
	{
		return N;
	}

	public void push(Item item)
	{
		Node oldFrist = frist;
		frist = new Node();
		frist.next = oldFrist;
		frist.item = item;
		N++;
	}

	public Item pop()
	{
		Item item = frist.item;
		frist = frist.next;
		N--;
		return item;
	}

	@Override
	public Iterator<Item> iterator() {
		// TODO Auto-generated method stub
		return new LinkedStackIterator();
	}
	private class LinkedStackIterator implements Iterator<Item>
	{

		private Node current = frist;
		@Override
		public boolean hasNext() {
			// TODO Auto-generated method stub
			return current != null;
		}

		@Override
		public Item next() {
			// TODO Auto-generated method stub
			Item item = current.item;
			current = current.next;
			return item;
		}

		@Override
		public void remove() {
			// TODO Auto-generated method stub

		}

	}

}

先进先出队列(链表实现)：

import java.util.Iterator;

public class LinkedQueue<Item> implements Iterable<Item>
{
	public class Node
	{
		Item item;
		Node next;
	}

	private Node frist;
	private Node last;

	private int N = 0;

	public boolean isEmpty()
	{
		return frist == null;
	}
	public int size()
	{
		return N;
	}

	public void enqueue(Item item)
	{
		Node oldLast = last;
		last = new Node();
		last.item = item;
		last.next = null;
		if(isEmpty())
		{
			frist = last;
		}
		else
		{
			oldLast.next = last;
		}
		N++;
	}

	public Item dequeue()
	{
		Item item = frist.item;
		frist = frist.next;
		if(isEmpty())
		{
			last = null;
		}
		N--;
		return item;
	}

	@Override
	public Iterator<Item> iterator() {
		// TODO Auto-generated method stub
		return new LinkedQueueIterator();
	}

	private class LinkedQueueIterator implements Iterator<Item>
	{
		private Node current = frist;

		@Override
		public boolean hasNext() {
			// TODO Auto-generated method stub
			return current != null;
		}

		@Override
		public Item next() {
			// TODO Auto-generated method stub
			Item item = current.item;
			current = current.next;
			return item;
		}

		@Override
		public void remove() {
			// TODO Auto-generated method stub

		}

	}

}

版权声明：本文为博主原创文章，未经博主允许不得转载。