LeetCode Merge Two Sorted Lists

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

题目描写叙述：

类似曾经C语言做的输入两个链表。依照顺序大小将其连接。

只是这次试着用JAVA做。思路还是一样。

代码：

/**
* Definition for singly-linked list.
* public class ListNode {
*     int val;
*     ListNode next;
*     ListNode(int x) {
*         val = x;
*         next = null;
*     }
* }
*/
public class Solution {
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
ListNode head;
if(l1==null) //推断是否有一个串是空串
return l2;
else if(l2==null)
return l1;

if(l1.val<l2.val){ //推断第一个结点
head = l1;
l1=l1.next;
}
else{
head = l2;
l2=l2.next;
}
ListNode temp = head;
while(l1!=null&&l2!=null)
{
if(l1.val<l2.val)//比較每个结点
{
temp.next = l1;
temp=temp.next;
l1 = l1.next;
}
else
{
temp.next = l2;
temp=temp.next;
l2 = l2.next;
}
}
if(l1==null) //一个串结束直接接上另外一个
temp.next=l2;
else
temp.next = l1;
return head;
}
}