Solution for LeetCode LeetCode: Swap nodes in Pairs
Leetcode Problem: Swap Nodes in Pairs
Given a linked list, swap every two adjacent nodes and return its head.
You may not modify the values in the list’s nodes, only nodes itself may be changed.
Explanation and solution
To solve this question, you need to master basic operation skills for link list, and how to swap two nodes.
The time complexity is $O(N)$.
Naive solution: Traversal link list and reverse it on fly
dummy node will simplify the operations.
The result is:
The code will be cleaner if we use recursive strategy, but it will be slower in time performance.