Linked List pattern

Merge Two Sorted Lists

Merge two sorted linked lists into one sorted list by splicing their nodes together, and return its head. Watch it run step by step, then write your own pseudocode and get it checked by AI.

  • LeetCode 21
  • Easy
  • 2 approaches
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Linked ListLeetCode 21

Easy

From the first idea to the best one

  1. 01 Naive · collect + sort O((n+m) log(n+m))O(n+m) space
  2. 02 Optimized · two pointers O(n + m)O(1) space
Each approach plays step by step, with its time and space.

What you will learn

  • How to read Merge Two Sorted Lists and spot the linked list pattern in it
  • Naive · collect + sort: O((n+m) log(n+m)) time, O(n+m) space
  • Optimized · two pointers: O(n + m) 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 Merge Two Sorted Lists 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.