I don't like using both declarations and expressions for functions.

The callback you pass into reduce can do everything, including parseInt

Also, the input range is given. Any good competitive programming participant should be able to judge the required complexity based on the input range ;-)

No reason for the backslash character. I just copied the mapping between letters from some page and it was there. It may be removed.

Short variables save time needed to code so simple things :P And I will never go back to this code so it doesn't matter. It's not a production.

I think the whole case+arr.push statement can be more easily (and more succintly) done with an object that maps certain Cyrillic characters to Latin characters.

Why did you add the backslash character?

I see you use very short variable names (c, e, al).
In most cases it's better to use variable names that clearly communicate what kind of value
they refer to.

On CW you can see quite a few katas sharing the task, but with different requirements:

• Performance or running time; e.g. this kata vs. Avanta's one (I made several katas of this type, all of which start with Insane in the title)
• Code size; check out many "One Line Task" katas out there :)
• The available language itself; check out the BF (Brainfxxk) katas.
• Others; banned characters or language constructs...

Please note that these cases do not violate the notion of "self-contained".

Well, its a 2kyu kata. What do you expect? :P

I did, but my experience with the katas on this website is that they are self-contained.

You surely didn't read the first line ;-)

Yes.

The only hint is the part where it says it'll have tests for big inputs. That's not very explicit.

Have you read the descriptions? ;-)

Good explanation, Thank you! Follower++