用python定义Node类和单链表类已知两个单链表a 和b 节点值为整数链表中节点按升序排列线编写代码将二者合并并输出所有单链表的元素。

# 定义节点类
class Node:
    def __init__(self, val):
        self.val = val
        self.next = None

# 定义单链表类
class LinkedList:
    def __init__(self):
        self.head = None

    def add(self, val):
        node = Node(val)
        if self.head is None:
            self.head = node
        else:
            curr = self.head
            while curr.next is not None:
                curr = curr.next
            curr.next = node

    def merge(self, b):
        a_curr = self.head
        b_curr = b.head
        merged_list = LinkedList()

        while a_curr is not None and b_curr is not None:
            if a_curr.val < b_curr.val:
                merged_list.add(a_curr.val)
                a_curr = a_curr.next
            else:
                merged_list.add(b_curr.val)
                b_curr = b_curr.next

        while a_curr is not None:
            merged_list.add(a_curr.val)
            a_curr = a_curr.next

        while b_curr is not None:
            merged_list.add(b_curr.val)
            b_curr = b_curr.next

        return merged_list

    def print_list(self):
        curr = self.head
        while curr is not None:
            print(curr.val, end=" ")
            curr = curr.next

# 示例代码
a = LinkedList()
a.add(1)
a.add(3)
a.add(5)
print("链表a: ", end="")
a.print_list()

b = LinkedList()
b.add(2)
b.add(4)
b.add(6)
print("\n链表b: ", end="")
b.print_list()

merged_list = a.merge(b)
print("\n合并后的链表: ", end="")
merged_list.print_list()
``