文章作者：Tyan
博客：noahsnail.com | CSDN | 简书
1. Description
Swapping Nodes in a Linked List
2. Solution
- Version 1
class Solution:
def swapNodes(self, head: ListNode, k: int) -> ListNode:
length = 0
ptr = head
while ptr:
length += 1
ptr = ptr.next
ptr = head
count = 0
while ptr:
count += 1
if count == k:
beginning = ptr
if count == length - k + 1
end = ptr
ptr = ptr.next
beginning.val, end.val = end.val, beginning.val
return head
- Version 2
class Solution:
def swapNodes(self, head: ListNode, k: int) -> ListNode:
ptr = head
for _ in range(1, k):
ptr = ptr.next
beginning = ptr
end = head
while ptr.next:
ptr = ptr.next
end = end.next
beginning.val, end.val = end.val, beginning.val
return head
