🧠 Before you code — what pattern fits?
In a linked list of even length n, node i is the twin of node n-1-i (0-indexed). The twin sum is node.val + twin.val. Given the head of a linked list of even length, return the maximum twin sum.
[5,4,2,1] → 6
[4,2,2,3] → 7
[1,100000] → 100001
🎬 Video explanation · NeetCodeIO
Your solution runs against 3 unit tests, including edge and large-value cases.
Loading...
Test console · 3 unit tests
Submit your code to run it against all 3 unit tests. Results appear here.
JavaScript, TypeScript & Python run sandboxed in your browser; other languages run on the execution server. Your code is saved locally as you type.