A VALID PALINDROME

As someone who is currently learning DSA (Data Structures and Algorithms) as a beginner, I wanted to try out some basic problems to understand the concepts better. One such interesting problem I attempted was about checking a palindrome using the two-pointer approach.

✨ What Is a Palindrome?

A palindrome is a word, number, or phrase that reads the same forwards and backwards.

For example:

• madam

• racecar

• 121

These are all palindromes because if you reverse them, they remain the same.

🔁 What Is the Two-Pointer Approach?

The two-pointer approach is a technique used mostly in array and string problems. In this method:

• One pointer starts from the beginning

• The other starts from the end

• Both pointers move towards the center while comparing values

This method is simple, fast, and works well when we need to check conditions between elements from both ends.

📝 Note: It only applies in sorted arrays, So it is also helpful in palindrome-related string problems.

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💡 The Palindrome Question I Solved

I picked a simple but interesting problem: We are given a string s2 = "Race a car" and we need to convert it to a new string s1 by removing all spaces and ignoring the case.

So:

s2 = "Race a car"

After removing spaces and converting to lowercase: s1 = "raceacar"

Now, the goal is to check whether s1 is a palindrome or not.

🔍 How I Approached the Problem

I carefully read the question and thought about it logically. I realized that this fits perfectly into the two-pointer method.

Here’s how:

• Compare the first and last letters

• Move the pointers inward

• Keep comparing until all characters are checked

If all characters match, the string is a palindrome. If not, then it isn’t.

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🧠 My Learning

From this small but meaningful problem, I learned:

• How to apply the two-pointer technique in real problems

• The importance of cleaning input data (like removing spaces and converting to lowercase)

• Thinking step-by-step and logically can really help solve even tricky problems

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🌸 Final Thought

I hope you find this short and simple story of mine helpful and interesting. If you're also starting your journey in DSA, try solving such problems on your own — it really helps build confidence and understanding

Let me know if you liked my approach, and feel free to share how you solved your first palindrome problem!