You are given a string num consisting of digits from $0$ to $9$. Your task is to return the largest possible palindromic number as a string by using some or all of the digits in num. The resulting palindromic number must not have leading zeros.

Note: You may reorder the digits freely, and you must use at least one digit from the num string.

Constraints:

• $1\leq$ num.length $\leq 1000$

• num consists of digits

Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding on how to solve this problem.

Implement your solution in the following coding playground.