Linked List pattern

Swap Nodes in Pairs

Given the head of a singly linked list, swap every two adjacent nodes and return the new head. You must swap the actual nodes rather than just their values. Watch it run step by step, then write your own pseudocode and get it checked by AI.

  • LeetCode 24
  • Medium
  • 2 approaches
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Linked ListLeetCode 24

Medium

From the first idea to the best one

  1. 01 Shortcut · swap values O(n)O(1) space
  2. 02 Optimized · rewire the pointers O(n)O(1) space
Each approach plays step by step, with its time and space.

What you will learn

  • How to read Swap Nodes in Pairs and spot the linked list pattern in it
  • Shortcut · swap values: O(n) time, O(1) space
  • Optimized · rewire the pointers: O(n) time, O(1) space
  • The pseudocode for each approach, its line lit as the animation runs
  • Practice: write your own pseudocode and get it checked

More Linked List

See Swap Nodes in Pairs run, step by step

Sign in and this page opens on the animation, with all 9 Linked List problems beside it.

Sign in to open itSee plans

DSA comes with the all labs plan and every ChaiCode batch.