Difficulty reconsideration for some problems in cpp track

Hi!

I’ve almost completed the cpp track and want to propose changing the difficulty of some problems, which, in my opinion, are too far from that actual difficulty in comparison to other problems on the track.

  1. Bank Account should be downgraded to medium (difficulty 6-7). Yes, concurrency is absolutely not a trivial topic to understand. Especially for someone who has just started learning programming. But on the other hand, the problem does not require implementing any algorithm. What is needed is to spend some time researching the problem and find a valid instrument in the std library.
    2.Zebra puzzle and Alphametics are the most difficult problems in the track and should be marked as hard (difficulty 8-9). They share the same class of problems - Contraint Satisfaction. This is not a beginner-friendly topic to understand and the algorithms for the proper solution (something more efficient than brute force and not hard code) are not trivial to implement. Are they really much easier thanSay or Binary Search Tree they are marked as difficulty 10 problems? I don’t think so.
  2. So, the say and binary search problems should be downgraded to difficulty 8 (hard).

These are the main tasks where I felt there was a clear mismatch between complexity and labeling. So the questions are:

  1. Do these suggestions make any sense?
  2. Do we need to discuss the changes for each problem separately, or can I just propose the actual changes and jump straight into PR?

Thanks.