Here's a Numberphile video that talks about embedding graphs. I think this happens because the subset of graphs that are able to be embedded in a plane is actually fairly limited.
Fun challenge, but the draggable area for the graphs is small, and it's not obvious where the boundaries are. I kept going past that boundary then realizing I can't set a vertex down.
Yeah, I was going to say, I've played a lot of this because I ran Kubuntu on my laptop for several years and Simon Tatham’s games are sort of our win-98-minesweeper.
Simon Tatham's puzzles are also available as mobile apps -- ad-free, and highly recommended -- and can also be played via the Web. The Signpost puzzle is my personal favourite. :)
The game is cool, but I think the title is overly general. It contaons a graph visualizer, which doesn't show much in the way of theory; and it's a railroad, not a playground.
the moving backgrounds are gonna give people issues.
i also had trouble reading the text on the backgrounds; consider changing the font colour to something that has significantly a different value (as in, Hue-Saturation-Value) from the background.
also as somebody has pointed out, the drag box felt tiny.
Changed a few colors, and added a background that makes the page lag. Didn't change the text or even the order of the levels. The small size of the bounding box is because he didn't expand it from the original.
The gotcha thing about this puzzle is sort of greedy approach; try to disentangle the local sub-graphs - concentrate on any nodes of your choice and their connections - and the global graph starts to fall in its place. It's trivial approaching it like this.
It's cool (well, not cool if these accusations of plagiarism are true, but superficially cool at least), but for some reason, the combination of frustration, tiny working area, and horrendous background really raised my anxiety levels.
Author: Simon Tatham <anakin@pobox.com>
Date: Sat Jul 16 19:51:53 2005 +0000
New puzzle: `Untangle', cloned (with the addition of random grid
generation) from a simple but rather fun Flash game I saw this
morning.
How much did you make via PayPal donations back then, if you don't mind my asking?
For anyone wanting to play it a bit bigger (albeit a bit blurry) and without the background you can load the iframe directly https://treksit.netlify.app/tron/
45 comments
[ 1.1 ms ] story [ 109 ms ] threadhttps://www.youtube.com/watch?v=xBkTIp6ajAg
https://www.chiark.greenend.org.uk/~sgtatham/puzzles/
The game is cool, but I think the title is overly general. It contaons a graph visualizer, which doesn't show much in the way of theory; and it's a railroad, not a playground.
i also had trouble reading the text on the backgrounds; consider changing the font colour to something that has significantly a different value (as in, Hue-Saturation-Value) from the background.
also as somebody has pointed out, the drag box felt tiny.
Also click on bonus area and then perturb the things.
[1] http://pulzed.com/ [2] https://treksit.netlify.app/credits.html
Plagiarism really does get my dander up.
The gotcha thing about this puzzle is sort of greedy approach; try to disentangle the local sub-graphs - concentrate on any nodes of your choice and their connections - and the global graph starts to fall in its place. It's trivial approaching it like this.
I wonder what an algorithmic approach to this would look like, would it act similarly?
The design was ispired by Wold of Goo :)
http://planarity.net/
It has a wikipedia page!
https://en.wikipedia.org/wiki/Planarity
Since Flash is dead I rewrote in JavaScript:
http://johntantalo.com/raphael.planarity/
Here's a short doc about how the puzzle generation algorithm works:
http://johntantalo.com/wiki/Planarity/