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PyAnimate

Interactive Python Lab

AI Wisdom

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PyAnimate

Interactive Python Lab

AI Wisdom

Interactive Python Lab

Palindrome Check

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Explain·Line by line

Replay·Step by step

Challenge·Guided prompts

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Data Flow Pipeline

beginner Track

Loop Explorer

Linear Search

Factorial (Iterative)

Fibonacci (Iterative)

Count Occurrences

Reverse a List

Palindrome Check

Find Min & Max

Sum & Average

FizzBuzz

Explain

Line 1

s = "madam" — a 5-character string.

Why this approach?

madam is a classic palindrome example. Strings in Python are immutable sequences of characters — every operation on a string creates a new one.

Structured Explanation

Overview

A palindrome reads the same forwards and backwards. Check by comparing the string to its reverse.

Analogy

'Racecar' — whether you start from the left or right, you read the same word.

Step-by-step

Clean the string: lowercase, remove non-alphanumerics.
Compare s == s[::-1].
For manual check: two-pointer — compare s[left] and s[right], move inward.

Visual

'racecar' → reversed='racecar' → equal → palindrome

Common mistakes

Forgetting to normalize case ('Racecar' ≠ 'racecar' before lower()).
Not removing spaces/punctuation for sentence palindromes.

Practice questions

Check 'A man a plan a canal Panama'.
Find the longest palindromic substring.

Time

O(n)

Space

O(n) for slice, O(1) for two-pointer

Complexity

Time

O(n)

Space

O(n)

Complexity Overview

O(1)

O(log n)

O(n)timespace

O(n log n)

O(n²)

n = 8range 1-20

AT N = 8

Complexity	Operations
O(1)	1
O(log n)	3
O(n)	8
O(n log n)	24
O(n²)	64

Challenge

Check if 'racecar', 'hello', and 'A man a plan a canal Panama' are palindromes.

Hint

For the last one, lowercase and remove spaces/punctuation first. Then use the two-pointer approach.

Code Studio