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Solution: Next Palindrome Using Same Digits

Explore how to find the smallest palindrome larger than a given numeric palindrome by rearranging its digits. Learn to use the two-pointer approach to modify only the left half of the string, identify positions for digit swaps, and create the next lexicographical permutation, optimizing the palindrome generation process.

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Statement

Given a numeric string, numStr, representing a palindromeA palindrome is a number that reads the same backward as it does forward. (composed only of digits). Return the smallest palindrome larger than numStr that can be created by rearranging its digits. If no such palindrome exists, return an empty string "".

Consider the following example to understand the expected output for a given numeric string:

  • input string = "123321"

  • The valid palindromes made from the exact digits are "213312", "231132", "312213", "132231", "321123".

  • We return the palindrome "132231" because it is the smallest palindrome larger than the input string "123321".

Constraints:

  • ...