Valid Palindrome

Commonly asked at:Meta Microsoft Amazon

Given a string, determine if it is a palindrome after converting all uppercase letters to lowercase and removing all non-alphanumeric characters.

Print true or false.

Example

Input: A man, a plan, a canal: Panama Output: true

Two pointers from both ends, skipping non-alphanumeric characters, comparing lowercased characters until they meet in the middle.

Not solved yet

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Editor

s = input()
cleaned = [c.lower() for c in s if c.isalnum()]
# TODO: two-pointer check
left, right = 0, len(cleaned) - 1

s = input()
cleaned = [c.lower() for c in s if c.isalnum()]
# TODO: two-pointer check
left, right = 0, len(cleaned) - 1

Input (stdin)

Output

Run your code to see output here.

Isolated sandbox · not executed on your devicePowered by Judge0 CE (free, self-hosted). Runs in an isolated sandbox — not on your device.

Editor

s = input()
cleaned = [c.lower() for c in s if c.isalnum()]
# TODO: two-pointer check
left, right = 0, len(cleaned) - 1

s = input()
cleaned = [c.lower() for c in s if c.isalnum()]
# TODO: two-pointer check
left, right = 0, len(cleaned) - 1

Input (stdin)

Output

Run your code to see output here.

Isolated sandbox · not executed on your devicePowered by Judge0 CE (free, self-hosted). Runs in an isolated sandbox — not on your device.

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