Validate string symmetric
Last updated: October 15, 2025
Quick Overview
Given a string, write a function to determine if it is symmetric, meaning it reads the same forwards and backwards, ignoring spaces, punctuation, and case differences. The function should return a boolean value: `true` if the string is symmetric and `false` otherwise. For example, the input "A man, a plan, a canal: Panama" should return `true`.
Twitter/X
October 15, 20252
17
1,576 solved
Given a string, write a function to determine if it is symmetric, meaning it reads the same forwards and backwards, ignoring spaces, punctuation, and case differences. The function should return a boolean value: `true` if the string is symmetric and `false` otherwise. For example, the input "A man, a plan, a canal: Panama" should return `true`.
Twitter/X uses this problem in the Onsite to evaluate your algorithmic thinking. They expect you to discuss multiple approaches, analyze trade-offs between them, and implement the optimal solution with clean, readable code.
What the Interviewer Expects
- Quickly identify the optimal approach and its theoretical basis
- Handle complex algorithm design with multiple interacting components
- Write concise, elegant code under time pressure
- Prove correctness of your approach and discuss alternative solutions
- Optimize beyond the obvious: discuss constant factor improvements
- Address follow-up variations and explain how the solution generalizes
Key Topics to Cover
How to Approach This
- Clarify input constraints and edge cases before writing code.
- Walk through your approach verbally and confirm with the interviewer before coding.
- Start with a brute force solution, then optimize. Mention time and space complexity.
- Test your solution with examples, including edge cases like empty input or duplicates.
- Consider common patterns: sliding window, two pointers, hash map, BFS/DFS, dynamic programming.
Possible Follow-up Questions
- What is the worst-case input for your solution?
- Can you solve this in a single pass?
- Can you optimize the space complexity of your solution?
Sharpen Your Skills on Codemia
Practice similar problems with our interactive workspace, get AI feedback, and track your progress.
Practice DSA ProblemsSample Answer
Problem Analysis
The problem requires us to determine if a given string is symmetric, meaning it reads the same forwards and backwards while ignoring spaces, punctuation, and case differences. This suggests the use of...
Approach
- Clean the String: First, we need to create a cleaned version of the string that removes non-alphanumeric characters and converts all characters to lower case. For example, from 'A man, a plan, ...
Submit Your Answer
