Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be changed.)
Question
Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be changed.)
Solution
Sure, here is a Python solution for swapping every two adjacent nodes in a linked list:
class ListNode:
def __init__(self, x):
self.val = x
self.next = None
def swapPairs(head):
dummy = ListNode(0)
dummy.next = head
current = dummy
while current.next and current.next.next:
first = current.next
second = current.next.next
first.next = second.next
current.next = second
current.next.next = first
current = current.next.next
return dummy.next
Here's how it works:
- We create a dummy node and point it to the head of the linked list. This dummy node will act as a placeholder for the new head of the list after we
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