Given a positive integer n, compute its digit frequency score.

The digit frequency score is calculated by finding the frequency of each unique digit present in n, multiplying each digit by its frequency, and summing these values together.

Return the total digit frequency score of n.

Constraints:

• $1 \leq$ n $\leq 10^9$

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.