Section 1Understand Problem
Section 01
Understand the problem
Restate the problem precisely. Interviewers reward candidates who pause, define the contract, and name the guarantees before coding.
Problem statement
A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric characters include letters and numbers. Given a string `s`, return `true` if it is a palindrome, or `false` otherwise.
Example
s = "A man, a plan, a canal: Panama" → true
Constraints
1 ≤ s.length ≤ 2 × 10⁵ · s consists only of printable ASCII characters
Audio recording unsupported on this browser.
WPM—Fillers0Pace—Thinking0%
Explain the problem in your own words
0 words0 chars
AI Review
Write your thinking above first.
Once you've drafted a response, click Submit for AI review and a senior engineer will critique your reasoning.
Ready to submit Section 1?
The reviewer will check whether you stated inputs, output, guarantees, and any assumption you flagged.
Write at least a couple of sentences explaining the problem before submitting.