題目

將兩個有序連結串列合併為一個新的有序連結串列並返回。新連結串列是通過拼接給定的兩個連結串列的所有節點組成的。 

示例：

輸入：1->2->4, 1->3->4
輸出：1->1->2->3->4->4

python程式碼實現：

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    def mergeTwoLists(self, l1, l2):
        """
        :type l1: ListNode
        :type l2: ListNode
        :rtype: ListNode
        """
        l=ListNode(0)
        f = l
        while l1  and l2  :
            if l1.val < l2.val:
                l.next = l1
                l1=l1.next
            else:
                l.next = l2
                l2 = l2.next
            l = l.next
        if l1 is not None:
            l.next=l1
        elif l2 is not None:
            l.next = l2

        return f.next