A nonrecursive backtracking solver for a specific two dimensional "T" tetromino puzzle
Puzzle:
Put 18 "T" tetronimos exactly into a 6x6x2 grid (such as seen in this video: https://www.youtube.com/watch?v=izKIq8RlZoY)
A backtracking nonrecursive solution is presented. Solution takes approximately 30 minutes to run on a 2015 MacBook Pro.
The solver also includes a (much slower) naive solver with some minor optimization. Takes about 24 hours to run on a 2015 MacBook Pro.