刷尽天下 -- LeetCode 19 -- Remove Nth Node From End of List(删除链表的倒数第N个节点)

题目如下：

采用双指针的方法，其思想是通过第二个指针将删除节点找出来，然后处理节点链接，参考代码如下：

class Solution:
    def removeNthFromEnd(self, head, n):
        """
        :type head: ListNode
        :type n: int
        :rtype: ListNode
        """
        head0 = ListNode(0)
        head0.next = head

        runner = head0
        walker = head0

        for i in range(n):
            runner = runner.next

        while runner.next:
            walker = walker.next
            runner = runner.next

        node = walker.next
        walker.next = node.next
        node.next = None
        return head0.next