---
title: Robots and mining ore, clay, obsidian, geodes - Advent of Code 2022 Day 19 with Ruby
slug: robots-and-mining-ore-clay-obsidian-geodes-advent-of-code-2022-day-19-with-ruby
published_at: 2022-12-20 02:00:07 +0000
updated_at: 2026-03-04 20:15:14 +0000
summary: 
description: Robots and mining ore, clay, obsidian, geodes - Advent of Code 2022 Day 19 with Ruby. Graph traversal problem with some optimizations.  Challenge: https://adventofcode.com/2022/day/19 Solution: https://gist.github.com/cjavdev/3d4df947d785d04bde080d3d4bf20b28  #ruby #adventofcode
tags: [cjav_dev, web development tutorials, web development for beginners, vim, ruby, advent of code, advent of code 2022, advent of code 2022 day 19, advent of code ruby, advent of code 2022 ruby, advent of code day 19 ruby, ruby tutorial, ruby solution, graph traversal, dynamic programming, Hash.clear]
views: 237
author: CJ Avilla
url: https://www.cjav.dev/videos/robots-and-mining-ore-clay-obsidian-geodes-advent-of-code-2022-day-19-with-ruby
youtube_url: https://www.youtube.com/watch?v=O1EWLebIaAU
youtube_id: O1EWLebIaAU
embed_url: https://www.youtube.com/embed/O1EWLebIaAU
thumbnail_url: https://i.ytimg.com/vi/O1EWLebIaAU/hqdefault.jpg
type: video
---

# Robots and mining ore, clay, obsidian, geodes - Advent of Code 2022 Day 19 with Ruby

*Published: December 20, 2022*
*Views: 237*

## Watch

[Watch on YouTube](https://www.youtube.com/watch?v=O1EWLebIaAU)

[![Robots and mining ore, clay, obsidian, geodes - Advent of Code 2022 Day 19 with Ruby](https://i.ytimg.com/vi/O1EWLebIaAU/hqdefault.jpg)](https://www.youtube.com/watch?v=O1EWLebIaAU)

## Description

Robots and mining ore, clay, obsidian, geodes - Advent of Code 2022 Day 19 with Ruby. Graph traversal problem with some optimizations.

Challenge: https://adventofcode.com/2022/day/19
Solution: https://gist.github.com/cjavdev/3d4df947d785d04bde080d3d4bf20b28

#ruby #adventofcode

## Transcript

foreign hey what's up welcome back we're solving another Advent of code problem for 2022 this is day 19. we're going to solve it with Ruby this one's called not enough minerals in this case we're going to use some Blueprints and we're going to make some robots with different minerals that are available and in order to solve this we're given lots of different potential blueprints for a factory of robots that are going to generate special kinds of robots that ultimately I know they're going to help us somehow they're going to save us somehow we get our input it's going to look something like this where we're going to have a blueprint and some ID for the blueprint and then how much it costs to build a robot we're going to have a an or robot that we can build with four ore clay robot we can build with two or obsidian robot costs three ore and 14 clay I don't know reminds me a little bit of Settlers of Catan or whatever the game and then each geode robot costs two ore and seven obsidian that's just for blueprint one for Blueprint 2 it's going to have different values and costs and spends and all of that and we need to use These Blueprints and figure out which blueprint is going to be the best one and so in order to do that we have 24 minutes and at each minute we can use a robot to mine the thing that it's specialized in so we can use an orb robot to mine one ore or we can we can build a robot with the factory and have that spit out in ore this is going to be like another one of those problems where we want to go down a bunch of different paths and find the optimal solution each path in this case is going to be let's go down and build blueprint one figure out how many geodes we can get out of it then we'll go down blueprint to figure out how many geodes we can get out of it so on and so forth this first section it says if you were to take blueprint one here are some things that you might do so you might start collecting or and collect some more ore and we're going to spend some of that word to create a clay collecting robot and then the next time we have two robots that are working one is collecting or one is collecting clay and then in the next several minutes we're going to start building up enough ore and clay in order to build a an obsidian collecting robot and so on and so forth until we have geode collecting robots which will collect geodes and at the end of the 24 minutes we want to know what the quality is of all of the different Blueprints and the way we figure out the quality is multiplying the ID of the blueprint number with the number of geodes that can be opened in 24 minutes with that blueprint okay so let's grab our input here so we'll grab these two Blueprints and we'll paste them in and in the actual input they're not going to be on new lines like this but it'll be helpful to start off like that we're going to say no arguments then we're going to be running against the test use case data is going to be data.readlines Chomp true otherwise data is going to be file.readlines of arcv DOT first Chomp true okay now we want to get our blueprints blueprints is going to be something like this we're going to say data Dot split on we'll split on new line or on a space and on a colon I think that should give us something pretty nice so for now we'll just like P blueprints of data and we want we so we actually want this to be all on one line but it can be I don't know it's handy to see it we'll just say data Dot first Ruby day 19. ARG Vida empty Ruby day 19. okay so this is what it's going to come out like where we'll have blueprint in one then each or costs for each clay cost whatever okay there we can use regular expressions or we could yeah let's just grab this whole thing open up rubular and create a regular expression for this it's going to be oops I didn't even grab it all let's just use our actual input first we'll just grab one of these actually yeah two of them just to make sure we're okay and then we're gonna grab another one of them make that a regular expression capture group capture group for the cost of different things robot costs for each clay Okay blah blah blah all right okay all right now we need to figure out what the IDS are each or robot costs or robot or each clay robot costs clay robot or so I'm gonna the the suffix here is going to be the material that we have to use to buy that kind of robot and then obsidian robot costs some amount of ore and some amount of Clay City and robot or an obsidian robot and then each geode robot costs some amount of ore this is going to be a geode or and geode obsidian all right so that should give us a match thing that we can use we'll just say match is this giant regular expression top match line so data dot each do line and we'll get some giant match back let's actually map it and then we want to create a dictionary or something that keeps track of all this stuff we'll say the ID is the match ID the robot or is robot or clay or obsidian robot or obsidian robot clay geode robot or geodobot obsidian and that should be all of our matches okay we're going to come back and we will add something fancy here that will be helpful for speeding up our algorithm we'll do that later let's print out what our first one looks like now blueprints data and then we'll pull this up all in one line run it okay so now we have these two objects or these two dictionaries that have the keys of ID or robot or clay robot or obsidian robot or City and robot clay et cetera et cetera and let's actually just change robot in all of these oh gosh whatever I was just going to make it bot because it'll shorten it a little bit clay bot all right whatever okay that's that's good enough okay once we have our blueprints we want to iterate over each of the blueprints and we need to figure out all the different options okay let's just make a new method here called Max geodes and this is going to take in a lot of arguments because we need this to handle all of our different stuff that we're passing in first of all it's going to take in the blueprint the current blueprint it's just going to take in one at a time it then it's going to take in how many or robots we have that's going to be a number of orobots clay robots obsidian robots geode robots then we need to know how much or we have Clay obsidian and geodes like how much we have of each of those things and then finally we need to know how much time we have left and in order to find the max geodes we're going to again use something like Max is equal to zero we're going to ultimately return Max and if we have enough money to buy a if we have enough money to buy an or robot we're going to recurse we also could just do nothing like we could we could purchase no robots and figure out how much or we would get clay obsidian and geodes based on our current robots maybe we want to say something like instead of Max is zero what if we make Max Max geodes of all of the same stuff we're going to pass in our blueprint our our or robots our clay robots obsidian robots geode robots our ore clay obsidian geodes and our time left minus one we don't want to increase our our geode robots but then each of our our resources are going to increase by the number of robots that we have creating that resource this is going to be like our or is going to go up by the number of ore Bots we have and the clay is going to go up by the number of clay Bots obsidian is going to go up by our obsidian Bots and geodes by our geode robots okay so this is this is the base one of the base cases right is that we don't actually buy any robots and we just keep recursing now if yeah if time left is zero then we want to return return geodes because that's how many that we have found once time is Once time is expired okay otherwise then we we have a few different cases can we buy an Orbot let's see if we have enough or to buy an Orbot then we can try by we can try buying an Orbot and that's going to be like Max is or yeah increase our orbots by one and then decrease our or by the blueprint but we also remember are going to continue increasing it by the number of or robots that we have or Bots and we're also going to increase clay we're going to increase obsidian we're going to increase geodes and we're going to say that that is going to cost us one minute to do now we're going to do the same exact thing with all of the other kinds of bots if or is greater than or equal to the blueprint for to build a clay bot and we want to bot then we want to build a clay bot okay this time we're buying a clay bot or building a clay bot and in order to build a clay bot were we're increasing we're going to continue already yeah it costs or to build a clay bot it does not cost clay will continue to increase based on the number of clay robots we have and our or is now going down because it costs ore to build a clay robot next we'll say can we build an obsidian bot the if we have more if we have an enough or and clay to build an obsidian bot then we should be good to go obsidian Bots are going to increase by one we'll pass our geodes we need to subtract the amount of obsidian bot or an obsidian bot clay from our resources there and we're going to say that again we're moving forward in time okay finally can we build a geode bot so in order to build a geode bot we need geode.org and geodebot obsidian and we're going to pass in our blueprint or Bots clay Bots obsidian Bots and now our geode Bots are going to increase but now we have to subtract our or based on how much we spent on our obsidian bot and we have to subtract our obsidian based on our obsidian bot and finally we are done okay okay this should give us at least the like ways that we're going to Fork when we can buy different robots now instead of calling these Macs I'm going to call them option and here we want to say something like Max equals option if option is greater than Max and the reason we're doing that is that we want to consider each of these different possible cases as we're iterating and okay so this is this is actually a pretty good start for Max geodes let's just call let's say that we have blueprints dot data.first we'll call this a B print and then we're going to call Max geodes for this blueprint and we start with one Aura robot that we just found and let's go 10 steps and see just see how long it takes and then we'll print out Max geodes for that first blueprint okay option undefined for nil class in Max geodes81 here we go I forgot to update all these okay run it again we get back zero why do we get back zero oh maybe this isn't enough steps like maybe we haven't actually created a geode yet so let's go 15 Steps I don't know how many it's going to take to get a geode 20 steps without the caching which we're going to do next I'm nervous that it's going to take forever all right so while that's running let's add some debugging all right so here let's add some output that will just print out all like all of our stuff we don't actually need the blueprint but we can print out everything else here that we got as arguments so that we can see how how it's traversing let's run this again and we get some fun output let's look and see we got the first four are going to be our different robot types then we're gonna the next four are gonna be all of our different resources so we got 14 or 32 clay zero obsidian and zero geodes and time is now once this is like the last second at the end a couple things to note about this because we have five and six uh we have five or robots and six clay robots those two are just gonna keep producing tons and tons of ore and Clay but if we're not actually using it to buy anything then it doesn't really it's not really useful and so we only need as many robots as we need to buy the most expensive kind of other the most expensive kind of robot if we look at if we look at our input here at all of these different things right and this is this is a an optimization that I saw Jonathan Paulson do if you haven't seen his channel go check it out he's get fast at solving these things if you want to see someone solve it really really quickly in python or in C plus plus go check out his channel but one of one of his sort of observations was that if you you can look at all of the different costs of things and you don't need more than how much something costs so in this case like the most clay you would need is 14 right in order to build an obsidian robot once you have more than 14 clay you can't really spend that in a given cycle you don't need you don't need more than 14 clay robots because at that point you could build an obsidian bot for every single step and you would still not run out of clay because you'd have 14 clay robots producing 14 and then consuming it every single step basically so there are certain limitations we can place on things here one of them that you might observe is that or in order to build an Aur robot you need four to build a clay robot you need two to build an obsidian robot you need three and to build a geode robot you need two four two three two most Aura robots you need in one step is going to be like four right because if you have an or robot that's producing for or then theoretically you could build anything that you want you could build an orobot you could build a clay robot obsidian robot or geode robot once we get to four or robots we can stop going down that path we don't want to build more or robots than we need to and so one thing that I like to do is in the in the blueprint here I want to say or Max and this is going to be the the max of the match for the robot or the clay ore or the or the orobot clay robot and obsidian robot and the geode or robot requirements whichever one has the most or requirements I'm going to grab the max of those and use that as my ormax and store that off in the blueprint that way I only have to do it one time to calculate that and then I'm going to use that or Max down here I'm going to say if or Max is greater than blueprint or or or the the or robots are greater than blueprint of the or Max then we don't need to make any more or robots we can do the same thing for the others right but the others we only have we only use clay on obsidian robots so we can just say if yeah so obsidian bot Clay is the same as the max so down here when we're considering building a clay robot we can say or we already have enough clay robots to create anything that we want finally do we want to build an obsidian bot the only thing that needs obsidian is the geode Bots we can say as long as we have more obsidian Bots than the maximum geode bot obsidian then we should be good to go and that's like the cost of the obsidian down here should we build an obsidian bot obsidian robots and the number of obsidian robots is less than or equal to that can we buy an or well I think I got this wrong if we have enough or and Clay robots are less than or equal to that and or robots are less than or equal to that all right so let's see how that runs okay now when we stop and we scroll up you'll notice that we're getting a little bit more obsidian that's going to be like the third to last column here this one one one and we're so we're starting to build up some obsidian actually so before we go too far one other pattern that you'll notice is that these are the these are the other than the blueprint this is the list of arguments that we're passing into our Max geode function it's possible that we have already seen this number of orobots and Clay robots and obsidian robots based on the different Forks that we've gone down it is a good point now to start caching to start caching our our calls to Max geodes let's just create a global constant called scene and this will be a hash and then we're going to just return scene of key if scene has that key and the key is going to be everything that was past the function except for the blueprint and then we'll update the scene key and set it equal to Max seen at the key is equal to Max at the bottom so that we keep track of what the maximum was and we can easily cache and return that all right so let's run this again and we got back to pretty quickly now let's let's use 24 and we'll run it and we're expecting nine all right we got back nine but that was super slow and that was just for one blueprint if we were to time this we're gonna get back some output if you haven't seen time before you can put time in front of any of these like unix commands and that will give you some basic tools for benchmarking while that's doing that there is another optimization that we can do and that is okay so that took 16 seconds total ish and 14 I don't know so this was like 14 seconds in user space 15 in system i o stuff and it used 98 CPU it I don't know slow to do one blueprint and we need to do we need to iterate over several blueprints each giving us those geodes we need to make this faster one way that we can make it faster is again if we if we print out the key and just try to build up an intuition about what's going on here you'll see that we continue to grow in or in clay and a little bit in obsidian but again like we have 20 ore here but we can't actually use 20 ore and so if we're looking at a row that looks like this and we have four or Bots six clay Bots two obsidian Bots and no geode Bots and we have 20 or that is basically the same as us having four or right because if we can only if we can only maximum like if we can only spend four or then it doesn't matter if we have four five six seven hundred or what matters is that we have four or more or and so when we're talking about our cache key if this is varying as it continues to grow then we're going to spend a lot of extra Cycles unnecessarily so one way that we can improve our caching in our cash hits is by taking the modulo of the maximum required for a given resource using that as a as part of our cache key instead of the raw value that way we have more cash hits and it doesn't actually matter what's greater than our maximum like usable what I'm going to do inside of our cache key here is say or mod blueprint of Max or in our clay mod blueprint of Max clay obsidian mod blueprint Mac obsidian but Max clay and Max obsidian don't exist maybe we should add those or yeah it's not even Max or it's or Max and for clay the most amount of clay that we need is Obsidian bot clay and the most obsidian we need is geode bot obsidian okay so now if we print our key you should notice that it's like modulo right so now the the biggest it's going to get is is the maximum value that we require all right so let's let's run this and see how long it takes printing out is going to slow us down here let's let's remove our print statement and see how fast it goes okay one second all right that's way better than so without the modulo it takes about 16 seconds with the modulo it takes 1.6 that's like an order of magnitude difference right and it's almost exactly an order of magnitude so let's add it back in and what we need to do now is now that we can figure out the maximum geodes we want to iterate over all of our Blueprints and calculate some value right okay we need to determine the quality level of each blueprint by applying the blueprint's ID number with the number of geodes so our quality number is going to be blueprint ID times the max geodes of blueprint and then we're gonna have one and this is going to give us our quality and this wants to know what do you get if you add up the quality level of all blueprints in the list okay we're just gonna maybe we'll just say sum is equal to zero sum plus equals quality and then we'll say puts sum at the end here and as we're as we're going through we'll just say puts yeah looking at blueprint whatever the idea is okay so we'll run this okay blueprint one blueprint two we got back the number 27 we should have gotten 33. that should have been the quality levels okay so let's run this test again against the second blueprint blueprints of data dot last and this should give us 24 I believe oh okay 12 times 2 should have given us the right answer ah okay what's going on here is that every time we're calling Max geodes it's reusing This Global variable for a hash and sometimes it's saying hey I already have that many or robots clay robots obsidian robots Etc but the cost for each blueprint is a little different and so what we need to do is in between each of these we have to clear out the cache we need a new cache every time there's a method called clear on hash so if you have a hash called A and A has some value in it and you look at a and it has some keys and values you can say ADOT clear if I can spell it right okay and that will remove all of the values that just wipes out all the values what we can do is say scene dot clear and that will reset our cache so now if we run this again against all of our test blueprints we should get back 33 and we do okay awesome that's 33. now let's run it against our so we've got to grab all of our input from here we're going to call Ruby d19 input let's actually time it also looking at blueprint one two three four five six some of them are faster than others right like it's going to be able to figure it out pretty quickly I think it costs less to generate some of them than others all right so we end up with 968 which is our oh it's not 994. why is that different I think there's a chance that we're excluding too many so I'm just going to add one to all of these different use cases uh just in case we are jumping the gun too far by expanding what we're modulo buying we should capture a wider area just by one and I think that might do it let's see oh also when we're running Ruby or this is this is I'm running Ruby 3.2 which I'm really excited for Ruby three two it's supposed to be much much faster and right now while we're in the preview I don't know if this is going to be true forever but you can do dash dash widget to use yet another just in time thing that makes it way faster yeah it should definitely I in my experience it certainly makes it faster than 3.2 there is three nine three okay nine okay so this hmm that didn't do it let's also make this plus one for our ormax just in case there's more or that we can create or if just in case we needed more or than exactly that Max I don't know off by one errors at the end of the day the number of geodes should not change because these parameters that we're using are these like heuristics are just constraining the problem space so we're not going out too far all right this was the answer 994. that is the solution for part one of the puzzle part two is you now have 32 minutes and instead of looking at all of the blueprints we're just going to look at the first three for part two this changes up a little bit now we're going to look at Prince is going to be blueprints of data dot take three and now we're going to say print study do blueprint and instead of going for 24 minutes we now need to go for 30 minutes or 32 minutes which is much longer and okay so the way that we calculate this is what do you get if you multiply these numbers together so don't worry about the quality levels just determine the largest number of geodes and multiply them together so we want to just get the max geodes and multiply that we'll say product times equals oh product equals one and then we'll P Pro and and then we just cross our fingers and pray that it's fast enough to actually finish before we before we go insane all right so again we'll add like a little thing here that tells us that we're printing it out and again we need to clear our cache and we should be good to go let's run that each blueprint is going to take much longer now because now we're going for 32 minutes instead of 24 minutes which is significantly more in terms of things we can build in Bots that we can build and geodes and the like the problem space just explodes every time you add a minute yeah for for every minute that we add to this problem we're extending it by a lot of computation the other thing that's fun to look at is the activity monitor here we can see Ruby is going to grow in memory as it's starting to build up that scene cache of all the different things it's checking out it's running pretty hot here 98 of the memory and we're just going to let it we're gonna Let It Rock boom all right with the magic of time and editing we have we have finished this is our answer it took about three minutes 15 seconds and that's not actually that bad right like you could you could wait that long for I think it was day 16 for part two I waited I didn't wait but I let it run for 80 minutes 80 minutes to know whether or not your code you wrote was successful that was killer as a web developer I want that immediate feedback I gotta have that immediate feedback but so this is day 19 additive code hopefully this was fun and useful this was a tricky one another sort of dynamic programming problem where we have to go down a lot of different potential problem spaces and then we have to try to constrain it in clever ways so that it doesn't explode in complexity thank you so much for watching I really appreciate your time and attention and yeah we've got six more days so hopefully we can successfully crank these up all right we'll see you next time the

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