Given a string s consisting of digits, return the number of unique substrings where every distinct digit present appears with the same frequency.

Note: A substring is a contiguous non empty sequence of characters within a string. Duplicate substrings must only be counted once.

Constraints:

• $1 \leq$ s.length $\leq 1000$

• s consists of digits.

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.