Merge Two Sorted Lists - LeetCode

Merge Two Sorted Lists - LeetCode

题目：

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.

分析：

我选择的方式是直接进行比较，并且新建一个空间储存排序结果。注意的一点就是链表l1和l2会移动到为None的地步。

代码：

class Solution:
    # @param two ListNodes
    # @return a ListNode
    def mergeTwoLists(self, l1, l2):
        if not l1 and not l2:
            return None
            
            
        l4 =l = ListNode(0)
        
        while l1 and l2:
            if l1.val >= l2.val:
                l.next=  ListNode(l2.val)
                l2 = l2.next
            elif l1.val < l2.val:
                l.next = ListNode(l1.val)
                l1 = l1.next
            l = l.next  
        if not l1 and l2:
                l.next = l2
        if not l2 and l1:
                l.next = l1
        return l4.next