编写函数实现基本运算方法。基本运算方法应包括创建链表、销毁链表、求链表长度、 求链表某一位置节点的值、查找值为 x 的节点所在位置、新增节点、插入节点、删除节点。 节点各数据域与指针请自行定义。

在编写函数实现基本链表操作时，我们需要先定义一个节点结构，通常包含一个数据域和指向下一个节点的指针。下面是一个简单的Python示例，展示了如何实现这些功能：

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

class LinkedList:
    def __init__(self):
        self.head = None

    # 创建链表
    def create_list(self, nodes=None):
        if not nodes:
            return
        for i in range(len(nodes)):
            if i == 0:
                self.head = Node(nodes[i])
            else:
                new_node = Node(nodes[i])
                current = self.head
                while current.next:
                    current = current.next
                current.next = new_node

    # 销毁链表（这里仅简单地置空）
    def destroy_list(self):
        self.head = None

    # 求链表长度
    def length(self):
        count = 0
        current = self.head
        while current:
            count += 1
            current = current.next
        return count

    # 查找值为x的节点位置
    def find_position(self, value):
        position = -1
        current = self.head
        for i in range(self.length()):
            if current.data == value:
                position = i
                break
            current = current.next
        return position

    # 新增节点
    def append(self, data):
        new_node = Node(data)
        if not self.head:
            self.head = new_node
            return
        current = self.head
        while current.next:
            current = current.next
        current.next = new_node

    # 插入节点
    def insert_at_position(self, position, data):
        if position < 0 or position > self.length():
            raise IndexError("Invalid position")
        if position == 0:
            new_node = Node(data)
            new_node.next = self.head
            self.head = new_node
        else:
            current = self.head
            for _ in range(position - 1):
                current = current.next
            new_node = Node(data)
            new_node.next = current.next
            current.next = new_node

    # 删除节点
    def delete_value(self, value):
        if not self.head:
            return
        if self.head.data == value:
            self.head = self.head.next
            return
        prev = None
        current = self.head
        while current and current.data != value:
            prev = current
            current = current.next
        if current is None:
            return
        prev.next = current.next

# 使用示例:
llist = LinkedList()
nodes = [1, 2, 3, 4, 5]
llist.create_list(nodes)
print("Length:", llist.length())
print("Find 3:", llist.find_position(3))
llist.append(6)
print("After appending 6:")
llist.insert_at_position(2, 7)
print("After inserting at position 2:")
llist.delete_value(4)