Easy Strings Question 10 of 224

How do you check if a string is a palindrome?

DSA interview set · Speak this in 60–90 seconds · Faridabad & Delhi NCR

Without indexScan every row

With indexJump to keys

CostWrites slower

Compare characters from both ends with two pointers and stop on a mismatch.

Why interviewers care about Strings:

This is a process

question about Strings.

Panels listen for order,

trade-offs, and what you would actually do on a DSA project - not buzzwords.

Stay structured

Name the idea, why it exists, then one short example.

Close cleanly

End with when you use it and one common pitfall.

Before you speak the answer, walk the interviewer through these steps:

1
Compare characters from both
ends with two pointers and stop on a mismatch.
2
Time is O(n) and
extra space is O(1) if you index the original string.
3
Reversing a copy is
easier to write but uses O(n) space, so mention both and prefer two pointers.
4
Give an example
One tiny concrete case you can say aloud.
5
Common mistake
What juniors usually get wrong.
6
Close
When you pick this over the alternative.

Here's a short line you can speak, broken into clear beats:

Say this line

“Time is O(n) and extra space is O(1) if you index the original string.”

Break into beats

TimeisOnandextra

Speaking order

2987408337471632900

Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.

Compare characters from both ends with two pointers and stop on a mismatch. Time is O(n) and extra space is O(1) if you index the original string.