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I spent two hours debugging issue.
Spoiler
In P1, I simply generated all combinations and calculated the area of each rectangle.
For P2, I initially struggled with sorting the 496 input points, not realizing they were already ordered sequentially to form a continuous polygon. This oversight cost me significant time in constructing the polygon. Moreover, the Spatial Match Tool produced inaccurate results for the largest area, forcing me to visually inspect and confirm the correct answer. To top it off, I spent about another two hours only to discover that my area calculation formula was incorrect.
For P2, I initially struggled with sorting the 496 input points, not realizing they were already ordered sequentially to form a continuous polygon. This oversight cost me significant time in constructing the polygon. Moreover, the Spatial Match Tool produced inaccurate results for the largest area, forcing me to visually inspect and confirm the correct answer. To top it off, I spent about another two hours only to discover that my area calculation formula was incorrect.
Pretty nice challenge today considering we're on Day 9! That is... (spoiler)
Spoiler
If you're not a complete idiot that spends 1.5 hours debugging spatial processing just to notice that your area calc isn't correct.
Shoutout @Hub119 for the Spatial Process prompt - didn't click on to what he was ranting about in the WhatsApp chat until I ran into that brick wall myself!
Shoutout @Hub119 for the Spatial Process prompt - didn't click on to what he was ranting about in the WhatsApp chat until I ran into that brick wall myself!
Part of the problem was difficult to understand, but it seems I took a long detour because I didn't read the problem carefully.
Spoiler
In order to create the outer polygon, I went to the trouble of finding combinations, rearranging the lines, and working hard to create the polygon, but all I needed to do was create it in the original order.
My 1st workflow.
Spoiler
Macro
After reading community.
Was determined to avoid using the Spacial tools, went down a complete rabbithole by building out a grid using formulas, realised the maths would never allow that to work, gave up and force myself to use Spacial.
Really wish I had, as it took a fraction of the time. And isn't that what AoC is supposed to be about, using things you don't typically use.
Spoiler
Thanks to those noting that Spacial Match didn't generate correct result, lost a lot of time on that, before taking Spacial Process approach.
Couldn't initially figure out how to generate the rectangle from the two points, before I learned about the bounded rectangle formula (thanks Google!).
Couldn't initially figure out how to generate the rectangle from the two points, before I learned about the bounded rectangle formula (thanks Google!).
Day 9
Spoiler
Thank god for spatial tools!
P1: Rather easy brute force by appending all points to each other then taking area of min/max points on rows/columns
P2: Took a bit on approach but landed on spatial. First I created a Sequence Polygon of all the points (don't forget to add the initial point to the end to close the loop). Then I created a bounding rectangle of point a, point b then point a again. From there, I did a spatial match where target within universe to see which bounding rectangles fit into the sequence polygon universe. From there, take the max area and bam, there you have it!
P1: Rather easy brute force by appending all points to each other then taking area of min/max points on rows/columns
P2: Took a bit on approach but landed on spatial. First I created a Sequence Polygon of all the points (don't forget to add the initial point to the end to close the loop). Then I created a bounding rectangle of point a, point b then point a again. From there, I did a spatial match where target within universe to see which bounding rectangles fit into the sequence polygon universe. From there, take the max area and bam, there you have it!
Day 9 is officially in the books! This was a really cool challenge, and yet another opportunity to get some practice with some seldom-used tools. We are now 3/4 done with AoC!
My Solutions
My Reflection:
Spoiler
Part 1 was super easy. Brute force took me all the way home. I made a list of every possible combination, calculated their areas, and isolated the largest one. Honestly, I probably could have skipped the part where I remove pairs of the same point, but oh well! At least it proves I am aware of the issues involved with cartesian joining a table to itself.
Part 2 was where things heated up, as usual! I heard rumblings all day about how spatial tools are super useful here (Given the fact we are working with a grid, this makes sense) but that Spatial Match was giving people trouble. That being said, it was my original plan while I was dreaming up answers to the question so I just HAD to try it. I started with the same combination of every pair of points and began calculating the missing corner points. Once I had those, I created a square polygon for each pair to act as my Targets. Then, I sequenced the original list of points and created a sequence polygon to act as my Universe. When I got a wrong answer (too high), I was like: "Hmm, the correct one must be right on the edge or something... I know! I will add a buffer to my sequence polygon!" (You fool, they said too high, and buffer would only make that worse!!) Anyways, a few more fumbles with spatial match occurred before I finally decided to scrap it. I almost scrapped spatial analysis entirely, but I had already come so far that I forced myself to at least drag a bunch of other spatial tools onto the canvas to see if it sparks any inspirations. Lucky for me, I eventually landed on the Spatial Process tool and realized that I might be able to work the other way around. That is to say, if removing the 'Universe' from a target polygon leaves you with nothing left, that means all of the target polygon was within the green/red squares, and that the pair in question is valid for the problem. After I made that discovery, I was free and clear!
Overall, this problem was really cool, and I am glad we are entering into the days where the tools become super niche. Even more so, I am glad to be a part of the community that helps me so much along the way. See you all tomorrow!
Part 2 was where things heated up, as usual! I heard rumblings all day about how spatial tools are super useful here (Given the fact we are working with a grid, this makes sense) but that Spatial Match was giving people trouble. That being said, it was my original plan while I was dreaming up answers to the question so I just HAD to try it. I started with the same combination of every pair of points and began calculating the missing corner points. Once I had those, I created a square polygon for each pair to act as my Targets. Then, I sequenced the original list of points and created a sequence polygon to act as my Universe. When I got a wrong answer (too high), I was like: "Hmm, the correct one must be right on the edge or something... I know! I will add a buffer to my sequence polygon!" (You fool, they said too high, and buffer would only make that worse!!) Anyways, a few more fumbles with spatial match occurred before I finally decided to scrap it. I almost scrapped spatial analysis entirely, but I had already come so far that I forced myself to at least drag a bunch of other spatial tools onto the canvas to see if it sparks any inspirations. Lucky for me, I eventually landed on the Spatial Process tool and realized that I might be able to work the other way around. That is to say, if removing the 'Universe' from a target polygon leaves you with nothing left, that means all of the target polygon was within the green/red squares, and that the pair in question is valid for the problem. After I made that discovery, I was free and clear!
Overall, this problem was really cool, and I am glad we are entering into the days where the tools become super niche. Even more so, I am glad to be a part of the community that helps me so much along the way. See you all tomorrow!
Since I take to Spatial tools about as well as vampires take to garlic, I only used one! And it wasn't the spatial match tool either!
Spoiler
So I only technically used one spatial tool to create a polygon, but I used a bunch of spatial functions!
Pt 1 -
Pretty similar to others, I did a cartesian join, removed dupes, calculated the area and found the max area.
Pt 2 -
Only because I had the advantage of reading WhatsApp comments about how spatial match tool was not being friendly (thanks @Hub119, your frustration saved me today!), I decided to cut my little rectangles from the "Big Spatial Obj" (I'm so technical), and then calculate the area of the cut object. I only kept where the cut object area was null or 0. For funsies, I did a within formula too - but that formula didn't always work. The cut objects with a 0 area were falsely excluded from my within formula.
Pt 1 -
Pretty similar to others, I did a cartesian join, removed dupes, calculated the area and found the max area.
Pt 2 -
Only because I had the advantage of reading WhatsApp comments about how spatial match tool was not being friendly (thanks @Hub119, your frustration saved me today!), I decided to cut my little rectangles from the "Big Spatial Obj" (I'm so technical), and then calculate the area of the cut object. I only kept where the cut object area was null or 0. For funsies, I did a within formula too - but that formula didn't always work. The cut objects with a 0 area were falsely excluded from my within formula.
