leetcode(8)-----Merge Two Sorted Lists

合并兩個有序連結清單

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.

Example:

Input: ->->, ->->
Output: ->->->->->
           

Python代碼實作

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
class Solution:
    def mergeTwoLists(self, l1, l2):
        head = ListNode()
        first = head
        while l1 != None and l2 != None:
            if l1.val>l2.val:
                head.next = l2
                l2 = l2.next
            else:
                head.next = l1
                l1 = l1.next
            head = head.next
        if l1== None:
            head.next = l2
        elif l2 == None:
            head.next = l1
        return first.next