Thank you!

Use spoiler flag next time, please. Your post was visible in the homepage.

just wow

An array of single character strings is a little weird. Why not an array of chars (aka a string)?

good

O(n * m)

How?

i wanted to do this but couldnt figure the logic out. nice solution tho

this was my solution!

Pienso que tu solucion se podria mejorar haciendo una copia de a en vez de modificarla

This is pretty similar to my solution but using forEach instead of a for loop. I like how simple your solution is though, espeically with the concatenation.

Ugly as heck. Why on earth would you omit white space? Why would you want your solution to be extra cryptic and extra difficult to read? Not even going to critique beyond "this is hard to look at"...

Not good at all, it's O(n²)

This helped me as well. Thank you for the explanation. I ended scrapping the the use of splice() simply becuase i couldnt figure that out. ended up just deleting the element in the list using delete and using filter to filter out falsy values that were not === 0 till i got what was needed. This was helpful to understand though. Thanks again