Collect stars by helping Santa solve puzzles. Two puzzles will be made available on each day in the Advent calendar; the second puzzle is unlocked when you complete the first. Each puzzle grants one star. Good luck! (egg: Also, some puzzles contain Easter eggs like this one. Yes, I know it's not traditional to do Advent calendars for Easter.)
All numbers in the elves' list are in feet (egg: Yes, I realize most of these presents are luxury yachts.). How many total square feet of wrapping paper should they order?
Santa and Robo-Santa start at the same location (delivering two presents to the same starting house), then take turns moving based on instructions from the elf, who is eggnoggedly (egg: This absolutely real word was invented by someone flipping eggnoggedly through a dictionary.) reading from the same script as the previous year.
Santa needs help mining some AdventCoins (egg: Hey, mined your own business!) (very similar to bitcoins) to use as gifts for all the economically forward-thinking little girls and boys.
It contains at least three vowels (aeiou only), like aei, xazegov, or aeiouaeiouaeiou (egg: John Madden John Madden John Madden).
Because your neighbors keep defeating you in the holiday house decorating contest year after year, you've decided to deploy one million lights in a 1000x1000 grid (egg: Hey, be glad I'm not asking for the resistance between two points!).
This year, Santa brought little Bobby Tables a set of wires and bitwise logic gates! Unfortunately, little Bobby is a little under the recommended age range, and he needs help assembling the circuit (egg: You had one of these as a kid, right?).
It is common in many programming languages to provide a way to escape (egg: It is common for many programmers to try to escape from string escaping. No such luck here.) special characters in strings. For example, C, JavaScript, Perl, Python, and even PHP handle special characters in very similar ways.
This year, however, he has some new locations (egg: Bonus points if you recognize all of the locations.) to visit; his elves have provided him the distances between every pair of locations. He can start and end at any two (different) locations he wants, but he must visit each location exactly once. What is the shortest distance he can travel to achieve this?
Now, starting again with the digits in your puzzle input, apply this process 50 (egg: Only because any longer started taking alarmingly long on my test hardware, and I wanted to avoid excluding people.) times. What is the length of the new result?
Santa's password expired again (egg: The corporate policy says your password expires after 12 seconds. For security.). What's the next one?
You will not encounter (egg: Nor are you likely to be eaten by a grue... during this puzzle, anyway.) any strings containing numbers.
For example, suppose you have only four attendees planned, and you calculate (egg: Finding a method to calculate happiness units is left as an exercise for the reader.) their potential happiness as follows:
Instead, at the end of each second, he awards one point to the reindeer currently in the lead. (If there are multiple reindeer tied for the lead, they each get one point.) He keeps the traditional 2503 second time limit, of course, as doing otherwise would be entirely ridiculous (egg: It also risks choosing a duration that isn't coprime with the cycle times of each reindeer.).
For instance, suppose you have these two ingredients (egg: * I know what your preference is, but...):
Several seemingly random breeds of dog (egg: It can tell them apart by their distinct Dog Residue.): samoyeds, pomeranians, akitas, and vizslas.
While playing with all the containers in the kitchen, another load of eggnog arrives (egg: Apparently, Amazon ships to the North Pole now.)! The shipping and receiving department is requesting as many containers as you can spare.
After the million lights incident, the fire code has gotten stricter: now, at most ten thousand lights (egg: This is an outrage! We're going to the next town hall meeting.) are allowed. You arrange them in a 100x100 grid.
Molecule fabrication always begins with just a single electron (egg: It's a Red-Nosed Reindeer electron.), e, and applying replacements one at a time, just like the ones during calibration.
To keep the Elves busy, Santa has them deliver some presents by hand, door-to-door (egg: This was before the Elves unionized, apparently.). He sends them down a street with infinite houses numbered sequentially: 1, 2, 3, 4, 5, and so on.
Little Henry Case (egg: The sky above the battle is the color of television, tuned to a dead channel.) got a new video game for Christmas. It's an RPG, and he's stuck on a boss. He needs to know what equipment to buy at the shop. He hands you the controller.
Little Henry Case decides that defeating bosses with swords and stuff is boring. Now he's playing the game with a wizard (egg: Being a !@#$% Sorcerer.). Of course, he gets stuck on another boss and needs your help again.
Little Jane Marie just got her very first computer for Christmas from some unknown benefactor (egg: Definitely not Wintermute.). It comes with instructions and an example program, but the computer itself seems to be malfunctioning. She's curious what the program does, and would like you to help her run it.
Furthermore, Santa tells you, if there are multiple ways to arrange the packages such that the fewest possible are in the first group, you need to choose the way where the first group has the smallest quantum entanglement to reduce the chance of any "complications" (egg: Santa does not elaborate on what he means by this, but the cringe he makes indicates that it wouldn't be pretty.). The quantum entanglement of a group of packages is the product of their weights, that is, the value you get when you multiply their weights together. Only consider quantum entanglement if the first group has the fewest possible number of packages in it and all groups weigh the same amount.
The codes are printed on an infinite sheet of paper (egg: The paper is very thin so it can be folded up neatly into the manual.), starting in the top-left corner. The codes are filled in by diagonals: starting with the first row with an empty first box, the codes are filled in diagonally up and to the right. This process repeats until the infinite paper is covered. So, the first few codes are filled in in this order:
Santa's sleigh uses a very high-precision clock (egg: An atomic clock is too inaccurate; he might end up in a wall!) to guide its movements, and the clock's oscillator is regulated by stars. Unfortunately, the stars have been stolen... by the Easter Bunny. To save Christmas, Santa needs you to retrieve all fifty stars by December 25th.
You finally arrive at the bathroom (it's a several minute walk from the lobby so visitors can behold the many fancy conference rooms and water coolers on this floor) and go to punch in the code. Much to your bladder's dismay, the keypad is not at all like you imagined it. Instead, you are confronted with the result of hundreds of man-hours of bathroom-keypad-design meetings: (egg: User Group 143 found a diamond shape to be the most environmentally friendly.)
In a valid triangle, the sum of any two sides must be larger than the remaining side. For example, the "triangle" given above is impossible (egg: Unless it's on a sphere!), because 5 + 10 is not larger than 25.
The room names are encrypted by a state-of-the-art shift cipher, which is nearly unbreakable without the right software (egg: ...or, like, half of a napkin.). However, the information kiosk designers at Easter Bunny HQ were not expecting to deal with a master cryptographer like yourself.
As the door slides open, you are presented with a second door that uses a slightly more inspired (egg: This one says 'WOPR' in block letters.) security mechanism. Clearly unimpressed by the last version (in what movie is the password decrypted in order?!), the Easter Bunny engineers have worked out a better solution.
In this modified code (egg: Please don't try this at home.), the sender instead transmits what looks like random data, but for each character, the character they actually want to send is slightly less likely than the others. Even after signal-jamming noise, you can look at the letter distributions in each column and choose the least common letter to reconstruct the original message.
An IP supports TLS if it has an Autonomous Bridge Bypass Annotation, or ABBA (egg: Any similarity to the pattern it describes is purely coincidental.). An ABBA is any four-character sequence which consists of a pair of two different characters followed by the reverse of that pair, such as xyyx or abba. However, the IP also must not have an ABBA within any hypernet sequences, which are contained by square brackets.
Unfortunately, the screen has been smashed (egg: BUT BY WHOM?!). After a few minutes, you've taken everything apart and figured out how it works. Now you just have to work out what the screen would have displayed.
In version two, the only difference is that markers within decompressed data are decompressed. This, the documentation explains, provides much more substantial compression capabilities, allowing many-gigabyte files to be stored in only a few kilobytes (egg: "It's the bomb!", the documentation claims.).
What do you get (egg: What do you get if you multiply six by nine?) if you multiply together the values of one chip in each of outputs 0, 1, and 2?
The experimental RTGs (egg: The previous version, model number PB-NUK, used Blutonium.) have poor radiation containment, so they're dangerously radioactive. The chips are prototypes and don't have normal radiation shielding, but they do have the ability to generate an electromagnetic radiation shield when powered. Unfortunately, they can only be powered by their corresponding RTG. An RTG powering a microchip is still dangerous to other microchips.
You remotely connect to the monorail control systems and discover that the boot sequence expects a password. The password-checking logic (your puzzle input) is easy to extract, but the code it uses is strange: it's assembunny (egg: Strangely, this assembunny code doesn't seem to be very good at multiplying.) code designed for the new computer you just assembled. You'll have to execute the code and get the password.
You arrive at the first floor of this new building to discover a much less welcoming environment than the shiny atrium of the last one. Instead, you are in a maze of twisty little cubicles (egg: You are in a twisty alike of little cubicles, all maze.), all alike.
In order to communicate securely with Santa while you're on this mission, you've been using a one-time pad that you generate using a pre-agreed algorithm (egg: This also happens to be the plot of World War II.). Unfortunately, you've run out of keys in your one-time pad, and so you need to generate some more.
Part of the sculpture is even interactive! When a button is pressed, a capsule is dropped and tries to fall through slots in a set of rotating discs to finally go through a little hole at the bottom and come out of the sculpture. If any of the slots aren't aligned with the capsule as it passes, the capsule bounces off the disc and soars away. You feel compelled to get one of those capsules (egg: These machines are everywhere in Japan, but on a MUCH smaller scale.).
You're done scanning this part of the network, but you've left traces of your presence. You need to overwrite some disks (egg: If I ever find one of my disks overwritten with a dragon curve, I'll know it was you.) with random-looking data to cover your tracks and update the local security system with a new checksum for those disks.
After going DU (and then hashing hijklDU to get 528e), only the right door is open; after going DUR, all doors lock. (Fortunately, your actual passcode is not hijkl (egg: It took four days to rescue the engineer that tried this.)).
No egg found
The Elves contact you over a highly secure emergency channel. Back at the North Pole, the Elves are busy misunderstanding (egg: Eggnoggedly misunderstanding them, actually.) White Elephant parties.
You'd like to set up a small hidden computer here so you can use it to get back into the network (egg: I'll create a GUI interface using Visual Basic... see if I can track an IP address.) later. However, the corporate firewall only allows communication with certain external IP addresses.
The computer system you're breaking into uses a weird scrambling function (egg: I do not like them, Security-Account-Manager-I-Am! I do not like scrambled letters and hash!) to store its passwords. It shouldn't be much trouble to create your own scrambled password so you can add it to the system; you just have to implement the scrambler.
You can instruct a node to move (egg: You suspect someone misunderstood the x86 MOV instruction.) (not copy) all of its data to an adjacent node (if the destination node has enough space to receive the data). The sending node is left empty after this operation.
No egg found
It's not a very fast little robot (egg: The Brave Little Air Duct Cleaning Robot That Could), but you reconfigure it to be able to interface with some of the exposed wires that have been routed through the HVAC system. If you can direct it to each of those locations, you should be able to bypass the security controls.
Nothing happens. (egg: Then again, if something ever works on the first try, you should be very suspicious.)
The night before Christmas, one of Santa's Elves calls you in a panic. "The printer's broken! We can't print the Naughty or Nice List!" By the time you make it to sub-basement 17 (egg: Floor 17: cafeteria, printing department, and experimental organic digitization equipment.), there are only a few minutes until midnight. "We have a big problem," she says; "there must be almost fifty bugs in this system, but nothing else can print The List. Stand in this square, quick! There's no time to explain; if you can convince them to pay you in stars, you'll be able to--" She pulls a lever and the world goes blurry.
"Based on what we're seeing, it looks like all the User wanted is some information about the evenly divisible values in the spreadsheet. Unfortunately, none of us are equipped for that kind of calculation - most of us specialize in bitwise operations (egg: Bonus points if you solve this part using only bitwise operations.)."
You come across an experimental new kind of memory stored on an infinite two-dimensional grid (egg: Good thing we have all these infinite two-dimensional grids lying around!).
No egg found
An urgent interrupt (egg: Later, on its turn, it sends you a sorcery.) arrives from the CPU: it's trapped in a maze of jump instructions, and it would like assistance from any programs with spare cycles to help find the exit.
In this area, there are sixteen memory banks (egg: There are also five currency banks, two river banks, three airplanes banking, a banked billards shot, and a left bank.); each memory bank can hold any number of blocks. The goal of the reallocation routine is to balance the blocks between the memory banks.
Wandering further through the circuits of the computer, you come upon a tower of programs (egg: Turtles, all the way down.) that have gotten themselves into a bit of trouble. A recursive algorithm has gotten out of hand, and now they're balanced precariously in a large tower.
You receive a signal (egg: There's that sorcery I told you about.) directly from the CPU. Because of your recent assistance with jump instructions, it would like you to compute the result of a series of unusual register instructions.
A large stream blocks your path. According to the locals, it's not safe to cross the stream (egg: "Don't cross the streams!", they yell, even though there's only one. They seem to think they're hilarious.) at the moment because it's full of garbage. You look down at the stream; rather than water, you discover that it's a stream of characters.
You come across some programs that are trying to implement a software emulation of a hash based on knot-tying. The hash these programs are implementing isn't very strong, but you decide to help them anyway. You make a mental note to remind the Elves later not to invent their own cryptographic functions (egg: NEW CRYPTOSYSTEM WHO DIS).
The hexagons ("hexes") in this grid (egg: Raindrops on roses and whiskers on kittens.) are aligned such that adjacent hexes can be found to the north, northeast, southeast, south, southwest, and northwest:
For some reason, though, some of these messages aren't ever reaching their intended recipient, and the programs suspect that some pipes (egg: Yes, citizens, plumbing! It's the latest invention to hit Rome!) are missing. They would like you to investigate.
No egg found
No egg found
Here, you encounter a pair of dueling generators (egg: I guess they are a little banjo-shaped. Why do you ask?). The generators, called generator A and generator B, are trying to agree on a sequence of numbers. However, one of them is malfunctioning, and so the sequences don't always match.
There are sixteen programs in total, named a through p. They start by standing in a line (egg: This is called a 'newline'.): a stands in position 0, b stands in position 1, and so on until p, which stands in position 15.
Suddenly, whirling in the distance, you notice what looks like a massive, pixelated hurricane (egg: You know, as opposed to all those non-pixelated hurricanes you see on TV.): a deadly spinlock. This spinlock isn't just consuming computing power, but memory, too; vast, digital mountains are being ripped from the ground and consumed by the vortex.
snd X plays a sound (egg: I don't recommend actually trying this.) with a frequency equal to the value of X.
Somehow, a network packet got lost (egg: I know how fast it's going, but I don't know where it is.) and ended up here. It's trying to follow a routing diagram (your puzzle input), but it's confused about where to go.
Suddenly, the GPU contacts you, asking for help (egg: ...as if millions of graphics pipelines suddenly cried out for help, but suddenly started working on something else instead because they all have to do the same thing at the same time and can't spend very long asking for help.). Someone has asked it to simulate too many particles, and it won't be able to finish them all in time to render the next frame at this rate.
You find a program trying to generate some art. It uses a strange process that involves repeatedly enhancing (egg: This technique is also often used on TV.) the detail of an image through a set of rules.
Diagnostics indicate that the local grid computing cluster has been contaminated with the Sporifica Virus. The grid computing cluster is a seemingly-infinite (egg: The infinite is possible at AdventOfCodeCom.) two-dimensional grid of compute nodes. Each node is either clean or infected by the virus.
No egg found
No egg found
Following the twisty passageways deeper and deeper into the CPU, you finally reach the core (egg: Get it? CPU core?) of the computer. Here, in the expansive central chamber, you find a grand apparatus that fills the entire room, suspended nanometers above your head.
"We've detected some temporal anomalies," one of Santa's Elves at the Temporal Anomaly Research and Detection Instrument Station (egg: It's about as big on the inside as you expected.) tells you. She sounded pretty worried when she called you down here. "At 500-year intervals into the past, someone has been changing Santa's history!"
Outside the utility closet, you hear footsteps and a voice. "...I'm not sure either. But now that so many people have chimneys (egg: This is, in fact, roughly when chimneys became common in houses.), maybe he could sneak in that way?" Another voice responds, "Actually, we've been working on a new kind of suit that would let him fit through tight spaces like that. But, I heard that a few days ago, they lost the prototype fabric, the design plans, everything! Nobody on the team can even seem to remember important details of the project!"
The Elves managed to locate the chimney-squeeze prototype fabric for Santa's suit (thanks to someone (egg: WAS IT YOU) who helpfully wrote its box IDs on the wall of the warehouse in the middle of the night). Unfortunately, anomalies are still affecting them - nobody can even agree on how to cut the fabric.
You've sneaked (egg: Yes, 'sneaked'. 'Snuck' didn't appear in English until the 1800s.) into another supply closet - this time, it's across from the prototype suit manufacturing lab. You need to sneak inside and fix the issues with the suit, but there's a guard stationed outside the lab, so this is as close as you can safely get.
While the very latest in 1518 alchemical technology might have solved their problem eventually, you can do better. You scan the chemical composition of the suit's material and discover that it is formed by extremely long polymers (one of which is available (egg: I've always wanted a polymer!) as your puzzle input).
"Situation critical (egg: Why is the situation always critical? Why can't the situation just be boring for once?)," the device announces. "Destination indeterminate. Chronal interference detected. Please specify new target coordinates."
"We do need to find our way back to the North Pole, but we have higher priorities at the moment. You see, believe it or not, this box contains something that will solve all of Santa's transportation problems - at least, that's what it looks like from the pictures in the instructions." It doesn't seem like they can read whatever language it's in, but you can: "Sleigh kit. Some assembly required. (egg: Just some oak and some pine and a handful of Norsemen.)"
The sleigh is much easier to pull than you'd expect for something its weight. Unfortunately, neither you nor the Elves know which way (egg: It's North. Obviously.) the North Pole is from here.
You talk to the Elves while you wait for your navigation system to initialize (egg: Do you have any idea how long it takes to load navigation data for all of time and space?!). To pass the time, they introduce you to their favorite marble game.
It's no use; your navigation system simply isn't capable of providing walking directions (egg: At the iceberg, use any lane to turn left. Then, swim for eight thousand miles.) in the arctic circle, and certainly not in 1018.
Actually, you're the one fading. The falling sensation (egg: wheeeeeeeeeeeeeeeeee) returns.
The year 518 is significantly more underground than your history books implied. Either that, or you've arrived in a vast cavern network (egg: It's probably this one. Can never be too sure, though.) under the North Pole.
Seeing as how cart-and-track systems don't appear in recorded history for another 1000 years (egg: Time anomalies! How do they work?!), the Elves seem to be making this up as they go along. They haven't even figured out how to avoid collisions yet.
You finally have a chance to look at all of the produce moving around. Chocolate, cinnamon, mint, chili peppers, nutmeg, vanilla... the Elves must be growing these plants to make (egg: Please do not use a programming puzzle as a recipe for hot chocolate. I cannot guarantee your safety.) hot chocolate! As you realize this, you hear a conversation in the distance. When you go to investigate, you discover two Elves in what appears to be a makeshift underground kitchen/laboratory.
According to your calculations, the Elves are going to lose badly. Surely, you won't mess up the timeline too much if you give them just a little advanced technology (egg: See also: the plot of every Civilization game.), right?
Using the samples you collected, work out the number of each opcode (egg: This is one of my favorite puzzles.) and execute the test program (the second section of your puzzle input).
You arrive in the year 18. If it weren't for the coat (egg: Continuity!) you got in 1018, you would be very cold: the North Pole base hasn't even been constructed.
On the outskirts of the North Pole base construction project, many Elves are collecting lumber (egg: Trade wood for sheep?).
"In programs where flow control is required, the instruction pointer can be bound to a register so that it can be manipulated directly. This way, setr/seti can function as absolute jumps, addr/addi can function as relative jumps, and other opcodes can cause truly fascinating (egg: Good luck maintaining a program that uses a bitwise operation on its instruction pointer, though.) effects."
No egg found
Just kidding. (egg: The old time travel hole gag! Classic.) You're falling through time again.
This is it, your final stop: the year -483 (egg: Yes, really: there is no year zero.). It's snowing and dark outside; the only light you can see is coming from a small cottage in the distance. You make your way there and knock on the door.
You hit the "experimental emergency teleportation" button (egg: We've always had this button; we've just been too scared to press it.) on the device and push I accept the risk on no fewer than 18 different warning messages. Immediately, the device deploys hundreds of tiny nanobots which fly around the cavern, apparently assembling themselves into a very specific formation. The device lists the X,Y,Z position (pos) for each nanobot as well as its signal radius (r) on its tiny screen (your puzzle input).
The immune system and the infection each have an army (egg: On second thought, it's pretty similar to regular reindeer immune systems.) made up of several groups; each group consists of one or more identical units. The armies repeatedly fight until only one army has units remaining.
As you reach down, the reindeer looks up at you, accidentally (egg: It was not an accident.) bumping a button on your wrist-mounted device with its nose in the process - a button labeled "help".
Santa has become stranded at the edge of the Solar System while delivering presents to other planets! To accurately calculate his position in space, safely align his warp drive, and return to Earth in time to save Christmas, he needs you to bring him measurements (egg: If only you had time to grab an astrolabe.) from fifty stars.
You notify the Elves that the computer's magic smoke seems to have escaped (egg: Looks like SOMEONE forgot to change the switch to 'more magic'.). "That computer ran Intcode programs like the gravity assist program it was working on; surely there are enough spare parts up there to build a new Intcode computer!"
The wires twist and turn (egg: A jumble of twisty little wires, all alike.), but the two wires occasionally cross paths. To fix the circuit, you need to find the intersection point closest to the central port. Because the wires are on a grid, use the Manhattan distance for this measurement. While the wires do technically cross right at the central port where they both start, this point does not count, nor does a wire count as crossing with itself.
You arrive at the Venus fuel depot only to discover it's protected by a password. The Elves had written the password on a sticky note, but someone threw it out (egg: Look on the bright side - isn't it more secure if nobody knows the password?).
The air conditioner comes online! Its cold air feels good for a while, but then the TEST alarms start to go off. Since the air conditioner can't vent its heat anywhere (egg: Honestly, I'm not sure what you expected.) but back into the spacecraft, it's actually making the air inside the ship warmer.
Except for the universal Center of Mass (COM), every object in space is in orbit around exactly one other object (egg: What do you mean, Kerbal Space Program doesn't have accurate orbital physics?). An orbit looks roughly like this:
There are five amplifiers connected in series (egg: As you can see, I know exactly how rockets work.); each one receives an input signal and produces an output signal. They are connected such that the first amplifier's output leads to the second amplifier's input, the second amplifier's output leads to the third amplifier's input, and so on. The first amplifier's input value is 0, and the last amplifier's output leads to your ship's thrusters.
The Elves' spirits are lifted when they realize you have an opportunity to reboot one of their Mars rovers, and so they are curious if you would spend a brief sojourn on Mars. (egg: I'm not sorry.) You land your ship near the rover.
While BOOST (your puzzle input) is capable of boosting your sensors, for tenuous safety reasons (egg: Oh sure, NOW safety is a priority.), it refuses to do so until the computer it runs on passes some checks to demonstrate it is a complete Intcode computer.
Your job is to figure out which asteroid would be the best place to build a new monitoring station. A monitoring station can detect any asteroid to which it has direct line of sight - that is, there cannot be another asteroid exactly between them. This line of sight can be at any angle, not just lines aligned to the grid or diagonally (egg: The Elves on Ceres are clearly not concerned with honor.). The best location is the asteroid that can detect the largest number of other asteroids.
Based on the Space Law Space Brochure (egg: Just be glad it wasn't a full set of Space Law Space Books; the number of pages is astronomical.) that the Space Police attached to one of your windows, a valid registration identifier is always eight capital letters. After starting the robot on a single white panel instead, what registration identifier does it paint on your hull?
After a brief scan, you calculate the position of each moon (your puzzle input). You just need to simulate their motion so you can avoid them (egg: Or you could just leave, but where's the fun in that?).
The game didn't run because you didn't put in any quarters. Unfortunately, you did not bring any quarters (egg: You do have crew quarters, but they won't fit in the machine.). Memory address 0 represents the number of quarters that have been inserted; set it to 2 to play for free.
As you approach the rings of Saturn, your ship's low fuel indicator turns on. There isn't any fuel here, but the rings have plenty of raw material. Perhaps your ship's Inter-Stellar Refinery Union (egg: Yes, the acronym is intentional.) brand nanofactory can turn these raw materials into fuel.
Out here in deep space, many things can go wrong. Fortunately, many of those things have indicator lights (egg: Which indicator lights indicate when the indicator lights have failed?). Unfortunately, one of those lights is lit: the oxygen system for part of the ship has failed!
You're 3/4ths of the way through the gas giants. Not only do roundtrip signals to Earth take five hours (egg: In minutes, that's as many as thirty tens!), but the signal quality is quite bad as well. You can clean up the signal with the Flawed Frequency Transmission algorithm, or FFT.
Running the ASCII program on your Intcode computer will provide the current view of the scaffolds. This is output, purely coincidentally (egg: PURELY COINCIDENTALLY), as ASCII code: 35 means #, 46 means ., 10 starts a new line of output below the current one, and so on. (Within a line, characters are drawn left-to-right.)
You arrive at the vault only to discover (egg: To see the inspiration for this puzzle, look up 'Link to the Past Randomizer Multiworld'.) that there is not one vault, but four - each with its own entrance.
Unsure of the state of Santa's ship, you borrowed (egg: "borrowed") the tractor beam technology from Triton. Time to test it out.
Because there isn't much space on Pluto, the civilization that used to live here thrived by inventing a method for folding spacetime. Although the technology is no longer understood, mazes like this one provide a small glimpse into the daily life of an ancient Pluto citizen (egg: So really, this puzzle is more archaeology than math, right?).
The clear choice for this mission is a droid (egg: I picture the Bouncy enemy from Kirby games.) that can jump over the holes in the hull - a springdroid.
Digging through the ship's storage, you find a deck of space cards! Just like any deck of space cards (egg: What do you mean, you've never heard of space cards? They're all the rage in Zozo.), there are 10007 cards in the deck numbered 0 through 10006. The deck must be new - they're still in factory order, with 0 on the top, then 1, then 2, and so on, all the way through to 10006 on the bottom.
The droids have finished repairing as much of the ship as they can. Their report (egg: If you don't at least exhale sharply through your nose after reading this joke, we probably can't be friends.) indicates that this was a Category 6 disaster - not because it was that bad, but because it destroyed the stockpile of Category 6 network cables as well as most of the ship's network infrastructure.
You land on Eris, your last stop before reaching Santa. As soon as you do, your sensors start picking up strange life forms moving around: Eris is infested with bugs! With an over 24-hour roundtrip (egg: For a sad version of this story, look up Voices of a Distant Star.) for messages between you and Earth, you'll have to deal with this problem on your own.
First, that you might be too late: the internal temperature is -40 degrees (egg: This is the same in Fahrenheit and Celsius.).
After saving Christmas five years in a row, you've decided to take a vacation at a nice resort on a tropical island. Surely (egg: WHAT COULD GO WRONG), Christmas will go on without you.
Their password database seems to be a little corrupted: some of the passwords wouldn't have been allowed by the Official Toboggan Corporate Policy (egg: To ensure your safety, your password must be the following string...) that was in effect when they were chosen.
With the toboggan login problems resolved, you set off toward the airport. While travel by toboggan might be easy, it's certainly not safe: there's very minimal steering (egg: It looks like the toboggan steering system even runs on Intcode! Good thing you don't have to modify it.) and the area is covered in trees. You'll need to see which angles will take you near the fewest trees.
You can continue to ignore the cid field, but each other field has strict rules (egg: GLORY TO ARSTOTZKA) about what values are valid for automatic validation:
You write a quick program (egg: No problem!) to use your phone's camera to scan all of the nearby boarding passes (your puzzle input); perhaps you can find your seat through process of elimination.
As you finish the last group's customs declaration, you notice that you misread one word (egg: Don't worry, nobody ever misreads just one word in real life.) in the instructions:
Of course, the actual rules have a small (egg: 100%) chance of going several levels deeper than this example; be sure to count all of the bags, even if the nesting becomes topologically impractical!
You narrow the problem down to a strange infinite loop in the boot code (egg: A trendy new line of encrypted footwear?) (your puzzle input) of the device. You should be able to fix it, but first you need to be able to run the code in isolation.
The data appears to be encrypted with the eXchange-Masking Addition System (XMAS (egg: No relation.)) which, conveniently for you, is an old cypher with an important weakness.
You glance back down at your bag and try to remember why you brought so many adapters; there must be more than a trillion valid ways to arrange them! Surely, there must be an efficient way (egg: Definitely itertools.) to count the arrangements.
Floor (.) never changes (egg: Floor... floor never changes.); seats don't move, and nobody sits on the floor.
Your ferry made decent progress toward the island, but the storm came in faster than anyone expected (egg: At least it wasn't a Category Six!). The ferry needs to take evasive actions!
The shuttle company is running a contest (egg: This is why you should never let me design a contest for a shuttle company.): one gold coin for anyone that can find the earliest timestamp such that the first bus ID departs at that time and each subsequent listed bus ID departs at that subsequent minute. (The first line in your input is no longer relevant.)
If the bitmask bit is X, the corresponding memory address bit is floating (egg: Technically, since you're on a boat, they're all floating.).
While you wait for your flight, you decide to check in with the Elves back at the North Pole. They're playing a memory game and are ever so excited (egg: Of course they are.) to explain the rules!
Unfortunately, you can't actually read the words on the ticket (egg: This actually happened to me once, but I solved it by just asking someone.). You can, however, read the numbers, and so you figure out the fields these tickets must have and the valid ranges for values in those fields.
The experimental energy source is based on cutting-edge technology: a set of Conway (egg: Rest in peace, Conway.) Cubes contained in a pocket dimension! When you hear it's having problems, you can't help but agree to take a look.
As you look out the window and notice a heavily-forested continent slowly appear over the horizon, you are interrupted by the child sitting next to you. They're curious if you could help them with their math (egg: Or "maths", if you have more than one.) homework.
You land in an airport surrounded by dense forest. As you walk to your high-speed train, the Elves at the Mythical Information Bureau (egg: This is a purely fictional organization. Any resemblance to actual organizations, past or present, is purely coincidental.) contact you again. They think their satellite has collected an image of a sea monster! Unfortunately, the connection to the satellite is having problems, and many of the messages sent back from the satellite have been corrupted.
The high-speed train leaves the forest and quickly carries you south. You can even see a desert in the distance! Since you have some spare time, you might as well (egg: Just in case. Maybe they missed something.) see if there was anything interesting in the image the Mythical Information Bureau satellite captured.
You don't speak the local language, so you can't read any ingredients lists. However, sometimes, allergens are listed in a language you do understand. You should be able to use this information to determine which ingredient contains which allergen and work out which foods are safe (egg: I actually considered doing this once. I do not recommend it.) to take with you on your trip.
You lost to the small crab! Fortunately, crabs aren't very good at recursion. To defend your honor as a Raft Captain, you challenge the small crab to a game of Recursive (egg: For some reason, nobody wants to play Recursive Twilight Imperium with me.) Combat.
Due to what you can only assume is a mistranslation (you're not exactly fluent in Crab (egg: If I were going for a programming language pun here, I'd say you were a little... RUSTy.)), you are quite surprised when the crab starts arranging many cups in a circle on your raft - one million (1000000) in total.
The tile floor in the lobby is meant to be a living art exhibit (egg: I need one of these!). Every day, the tiles are all flipped according to the following rules:
The light turns green and the door unlocks. (egg: You notice the brand written on the side of the lock: Diffie, Hellman, and Merkle.) As you collapse onto the bed in your room, your pager goes off!