Q:
给定一个链表,旋转链表,将链表每个节点向右移动 k 个位置,其中 k 是非负数。
示例 1:
输入: 1->2->3->4->5->NULL, k = 2 输出: 4->5->1->2->3->NULL 解释: 向右旋转 1 步: 5->1->2->3->4->NULL 向右旋转 2 步: 4->5->1->2->3->NULL
链接:https://leetcode-cn.com/problems/rotate-list/description/
思路:
代码:
# Definition for singly-linked list.
# class ListNode(object):
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution(object):
def rotateRight(self, head, k):
"""
:type head: ListNode
:type k: int
:rtype: ListNode
"""
if not head:
return []
stack=[]
pre = head
while pre.next:
stack.append(pre)
pre = pre.next
stack.append(pre)
move_ = k % len(stack)
if move_ == 0:
return head
new_head = stack[-move_]
stack[-move_-1].next = None
stack[-1].next = stack[0]
return new_head