Given a string s, reorder its characters so that characters with higher frequency appear before characters with lower frequencies.

All occurrences of the same character must be placed contiguously. If multiple characters have the same frequency, they may appear in any order.

Constraints:

• $1 \leq$ s.length $\leq 5 \cdot 10^5$

• s consists of uppercase English letters, lowercase English letters, and 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.