🧠 Before you code — what pattern fits?
Given an encoded string, return its decoded string. The encoding rule is k[encoded_string], where the encoded_string inside the brackets is repeated exactly k times. Nesting is allowed.
"3[a]2[bc]" → "aaabcbc"
"3[a2[c]]" → "accaccacc"
🎬 Video explanation · NeetCode
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.