Palindrome Checker
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Write a function that checks if the given string is a palindrome. A palindrome is a word, phrase, number, or other sequence of characters which reads the same backward as forward, ignoring cases, spaces, and punctuation.
Example 1
Input
[ "A man, a plan, a canal: Panama" ]
Output
true
Explanation. After ignoring punctuation, spaces, and case, 'AmanaplanacanalPanama' is a palindrome.
Example 2
Input
[ "race a car" ]
Output
false
Explanation. After cleaning up the string, 'raceacar' is not a palindrome.
Example 3
Input
[ " " ]
Output
true
Explanation. An empty string or a string with just spaces is considered a palindrome.
Example 4
Input
[ "Noon" ]
Output
true
Explanation. Ignoring the case, 'noon' is a palindrome.
Follow-up: Can you optimize your solution to run in O(n) time complexity?
Constraints:
The input string will not be null and will have at least one character. Consider only alphanumeric characters while ignoring cases.
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