Cops: Make a regex - Make a snake This is the cop's thread. The robber's thread is here.



Write a code that takes an input n and creates a n-by-n "snake matrix".

A snake matrix is a matrix that follows this pattern:

3-by-3:

1  2  3
6  5  4
7  8  9


and 4-by-4:

1   2   3   4
8   7   6   5
9   10  11  12
16  15  14  13


The exact output format is optional. You may for instance output [[1 2 3],[6 5 4],[7 8 9]], or something similar.

You must provide the language name, and a regex that fully matches your code. You can choose how detailed your regex should be. In the extreme, you can write a regex that matches every possible string, in which case it will be very easy to crack your code. You must also provide the output for n=4, so that robbers know the exact format you have opted for.

You may use one of the regex-flavors that are available on regex101.com, or the Ruby flavor.


PCRE (PHP)
Javascript
Python
Golang
Ruby


You must specify which one you are using.

Notes:


You must support any reasonably large n. You may assume it won't overflow the datatype or memory. If the default datatype is 8-bit signed integers, then you can assume n&lt;=11, if it's unsigned 8-bit integers, then you can assume n&lt;=15.
The robbers have to match the submission's output format, except leading/trailing spaces and newlines, since that might have been stripped away by the SE formatting.


Winning criterion:

The winner will be the uncracked submission with the shortest regex, measured in number of characters.

If your post has remained uncracked for 7 days, then you may post the intended solution and mark your submission as safe.
05AB1E, Cracked by mbomb007
Hopefully fun to crack and not too obvious.
Regex (PCRE):
^\w*[+\-*\/%]*\w*.{0,2}$

Output n=4:
[[1, 2, 3, 4], [8, 7, 6, 5], [9, 10, 11, 12], [16, 15, 14, 13]]

Original solution
UXFXLNX*+NFR}ˆ