题解 | #删除链表的倒数第n个节点#

# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param head ListNode类 
# @param n int整型 
# @return ListNode类
#
class Solution:
    def removeNthFromEnd(self , head: ListNode, n: int) -> ListNode:
        # write code here
        left = right = dummy = ListNode(0)
        left.next = right.next = dummy.next = head

        for _ in range(n):
            right = right.next
        
        while right.next:
            left = left.next
            right = right.next
        left.next = left.next.next
        return dummy.next