单链表创建

PS：头插法实现较简单，但生成内容为原内容的逆序；尾插法则为正序生成

class ListNode{
	public int val;
	public ListNode next;
	ListNode (int val) { this.val = val; }
}

public class ListTest {
	/**
	 * 头插法 
	 * @param nums
	 * @return
	 */
	public static ListNode headInsert(int[] nums)
	{
		ListNode head = null;
		ListNode tail = null;
		int len = nums.length, i=0;
		while (i < len)
		{
			tail = new ListNode(nums[i++]);
			tail.next = head;
			head = tail;
		}
		return head;
	}
	
	/**
	 * 尾插法 
	 * @param nums
	 * @return
	 */
	public static ListNode tailInsert(int[] nums)
	{
		ListNode head = null;
		ListNode tail = null;
		int len = nums.length, i = 0;
		while (i < len)
		{
			if (head == null)
			{
				head = tail = new ListNode(nums[i++]);
			}else 
			{
				tail.next = new ListNode(nums[i++]);
				tail = tail.next;
			}
		}
		tail.next = null;
		return head;
	}
	
	/**
	 * 遍历
	 * @param node
	 */
	public static void Traverse(ListNode node)
	{
		while (node != null)
		{
			System.out.println(node.val);
			node = node.next;
		}
	}

	public static void main(String[] args) {
		int arr[] = {1,2,3,4,5};
		ListNode head = null;
		head = headInsert(arr);
		//head = tailInsert(arr);
		Traverse(head);
	}

}