Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
Yes, it's a good solution in one line, but it does not use memory effective. We have a memory limit exception if parameter $n is huge number (for example, 1 Gb of memory is not enough if $n = 17 millions).
Array.range(-1, 1) should return [-1] not [-1, 0]
This comment is hidden because it contains spoiler information about the solution