Why the lines 295-317 are trying to modify the hash "bands"? That hash is supposed to stay frozen.

Question

https://code.sololearn.com/c74y6d7k9g6z/?ref=app

Answer 1

The trick is in lines 145-146.
cmodes = bands
modald = bands
When doing "bands.freeze" you're also freezing "cmodes" and "modald", hence the errors in lines 294-317 and 324-325 (which are not trying to modify "bands" but "cmodes" and "modald", respectively).
To fix the errors change lines 145-146 to this.
cmodes = bands.dup
modald = bands.dup

Answer 2

Thanks, bro!

Answer 3

Help, please.