Coding Challenge: Tromino Puzzles

One puzzle comes from a (now) classical induction exercise: "Show that any 2^n by 2^n grid with an arbitrary square removed can be tiled by L-shaped trominoes (pieces formed by three adjacent squares in the shape of an L)."

Another puzzle is a variation of the previous: "Which square can you remove from a 2^n by 2^n grid so that it is possible to tile it with straight trominoes (pieces formed by three adjacent squares in a row)?"

The coding challenge is to create an interactive version of either or both puzzles.

**References**
- S.W. Golomb, _Checker Boards and Polyominoes_, American Mathematical Monthly, **61** (1954), 675–682 [doi:10.1080/00029890.1954.11988548](https://doi.org/10.1080/00029890.1954.11988548)
- Norton Starr - [The Tromino Puzzle](https://nstarr.people.amherst.edu/puzzle.html)

**Examples**
- [CutTheKnot](https://www.cut-the-knot.org/Curriculum/Games/TrominoPuzzle.shtml) (it needs JAVA, so use chrome extension [cheerpJ](https://chrome.google.com/webstore/detail/cheerpj-applet-runner/bbmolahhldcbngedljfadjlognfaaein) to play with it )
- [Norton Starr & students](https://nstarr.people.amherst.edu/trom/puzzle-8by8/)