24. Swap Nodes in Pairs

Medium

Linked List,Recursion

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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.)

 

Example 1:

Input: head = [1,2,3,4]
Output: [2,1,4,3]

Example 2:

Input: head = []
Output: []

Example 3:

Input: head = [1]
Output: [1]

 

Constraints:

• The number of nodes in the list is in the range [0, 100].
• 0 <= Node.val <= 100

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Submissions

Time Submitted	Status	Runtime	Memory	Language
08/16/2022 21:36	Accepted	5 ms	7.5 MB	cpp
08/16/2022 21:36	Accepted	0 ms	7.6 MB	cpp
08/16/2022 21:30	Accepted	0 ms	7.6 MB	cpp