单向链表的删除和反转

今天部门测试，两道题：
1：删除一个单向链表中值为某个特定值的所有节点
2：把一个单向链表反转

第一个题目比较简单，第二个题目有点难，我吭哧半天没搞出来，丢人。。。

写在卷面上的答案要是搬到计算机上，100%得不到正确结果，呃，太依赖调试了。。。

Node类：

/**
 * chega
 * 2012-12-5下午2:55:52
 */

/**
 * @author chega
 *
 * 2012-12-5下午2:55:52
 *
 */
public class Node
{

	public int item;
	public Node next;
	
	public Node(int item){
		this.item = item;
		this.next = null;
	}
	
	public Node(int item, Node next){
		this.item = item;
		this.next = next;
	}
	
	public static Node createNodeList(int[] args){
		Node nextNode = null;
		Node node = null;
		for(int i=args.length-1; i>=0;i--){
			node = new Node(args[i], nextNode);
			nextNode = node;
		}
		return node;
	}
	
	@Override
	public String toString(){
		if(this.next == null){
			return this.item +"[next: null]";
		}else{
			return this.item +"[next: "+ this.next.item+"]";
		}
	}
	
	public String getDetailDesc(){
		StringBuilder sb = new StringBuilder();
		sb.append(this.item);
		Node head = this;
		while(head.next != null){
			sb.append("->" + head.next.item);
			head = head.next;
		}
		return sb.toString();
	}
}

删除节点：

/**
 * @author chega
 * 
 *         2012-12-5下午3:31:47
 * 
 */
public class DeleteNode
{
	Node	list	= Node.createNodeList(new int[] { 1, 1, 3, 5, 7, 9, 1, 1 });

	public static void main(String... args)
	{
		new DeleteNode().delete(1);
	}

	public void delete(int del)
	{
		System.out.println(list.getDetailDesc());
		Node currNode = list;//从链表的head开始
		Node previousNode = null;
		while (currNode != null)
		{
			if (currNode.item == del)
			{
				if (previousNode != null)
				{
					//删除当前节点：把当前节点的next赋值给上一个节点的next即可
					previousNode.next = currNode.next;
				}
				//如果previousNode == null说明删除的是链表的head，因此链表从head.next开始
				else
				{
					list = list.next;
				}
			}
			else
			{
				previousNode = currNode;
			}
			currNode = currNode.next;
		}

		System.out.println(list.getDetailDesc());
	}
}

反转链表：

/**
 * @author chega
 * 
 *         2012-12-5下午2:57:40
 * 
 */
public class ReverseOneWayNodeList
{

	Node	list	= Node.createNodeList(new int[]{1,3,5,7,9,1,2});

	public static void main(String... args)
	{
		new ReverseOneWayNodeList().reverseNodeList();
	}

	public void reverseNodeList()
	{
		//前一个节点
		Node previousNode = null;
		//后一个节点
		Node nextNode = null;
		//当前节点
		Node currNode = list;
		while(currNode!= null){
			nextNode = currNode.next;
			currNode.next = previousNode;
			previousNode = currNode;
			currNode = nextNode;
		}
		
		//把上一个节点赋值给单向链表
		list = previousNode;
		
		System.out.println(list.getDetailDesc());
	}
}