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Largest Palindromic Number (medium)
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Problem Statement

Given a string s containing 0 to 9 digits, create the largest possible palindromic number using the string characters. It should not contain leading zeroes.

A palindromic number reads the same backward as forward.

If it's not possible to form such a number using all digits of the given string, you can skip some of them.

Examples

Example 1

  • Input: s = "323211444"
  • Expected Output: "432141234"
  • Justification: This is the largest palindromic number that can be formed from the given digits.

Example 2

  • Input: s = "998877"
  • Expected Output: "987789"
  • Justification: "987789" is the largest palindrome that can be formed.

Example 3

  • Input: s = "54321"
  • Expected Output: "5"
  • Justification: Only "5" can form a valid palindromic number as other digits cannot be paired.

Constraints:

  • 1 <= num.length <= 10<sup>5</sup>
  • num consists of digits.

Try it yourself

Try solving this question here:

Python3
Python3
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