Problem 2.1: Remove Duplicates (100 pts)

Problem

Write a function remove_duplicates which takes in a sorted linked list of integers and mutates it so that all duplicates are removed.

编写一个函数 remove_duplicates，它接受一个已排序的整数链表，并修改它，以便移除所有重复的元素。

def remove_duplicates(lnk):
    """ Remove all duplicates in a sorted linked list.

    >>> lnk = Link(1, Link(1, Link(1, Link(1, Link(5)))))
    >>> Link.__init__, hold = lambda *args: print("Do not steal chicken!"), Link.__init__
    >>> try:
    ...     remove_duplicates(lnk)
    ... finally:
    ...     Link.__init__ = hold
    >>> lnk
    Link(1, Link(5))
    """
    "*** YOUR CODE HERE ***"

Hints

Hint1: Your implementation should mutate the original linked list lnk.

Hint2: DO NOT create new linked lists.

Hint3: DO NOT return the modified linked list.

Hint4: It is guaranteed that the linked list is acyclic.

你的实现应该修改原始链表 lnk。

• 不要创建新的链表。

• 不要返回修改后的链表。

• 保证该链表是不循环的。