{ "data": { "question": { "questionId": "125", "questionFrontendId": "125", "boundTopicId": null, "title": "Valid Palindrome", "titleSlug": "valid-palindrome", "content": "

A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric characters include letters and numbers.

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Given a string s, return true if it is a palindrome, or false otherwise.

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Example 1:

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\nInput: s = "A man, a plan, a canal: Panama"\nOutput: true\nExplanation: "amanaplanacanalpanama" is a palindrome.\n
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Example 2:

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\nInput: s = "race a car"\nOutput: false\nExplanation: "raceacar" is not a palindrome.\n
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Example 3:

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\nInput: s = " "\nOutput: true\nExplanation: s is an empty string "" after removing non-alphanumeric characters.\nSince an empty string reads the same forward and backward, it is a palindrome.\n
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Constraints:

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