You are given an integer num.

You can apply the following operation to num:

• Choose a digit $d$ ($0 \leq d \leq 9$) appearing in num.

• Choose a new digit $r$ ($0 \leq r \leq 9$).

• Replace every occurrence of $d$ in num with $r$.

Return the difference between the maximum value and the minimum value you can obtain by applying this operation independently for each case.

Note:

• The resulting number is allowed to have leading zeros.

• The chosen digit $d$ must be mapped to the same digit $r$ across all of its occurrences in num.

Constraints:

• $1 \leq$ num $\leq 10^8$

Now, 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 of how to solve this problem.

Implement your solution in the following coding playground.