114 lines
4.6 KiB
Plaintext
114 lines
4.6 KiB
Plaintext
Advent of Code
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• [About]
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• [AoC++]
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• [Events]
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• [Settings]
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• [Log Out]
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br0xen (AoC++) 4*
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<y>2016</y>
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• [Calendar]
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• [Leaderboard]
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• [Stats]
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• [Sponsors]
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--- Day 2: Bathroom Security ---
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You arrive at Easter Bunny Headquarters under cover of darkness. However, you left in such a rush that you forgot to
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use the bathroom! Fancy office buildings like this one usually have keypad locks on their bathrooms, so you search the
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front desk for the code.
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"In order to improve security," the document you find says, "bathroom codes will no longer be written down. Instead,
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please memorize and follow the procedure below to access the bathrooms."
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The document goes on to explain that each button to be pressed can be found by starting on the previous button and
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moving to adjacent buttons on the keypad: U moves up, D moves down, L moves left, and R moves right. Each line of
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instructions corresponds to one button, starting at the previous button (or, for the first line, the "5" button); press
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whatever button you're on at the end of each line. If a move doesn't lead to a button, ignore it.
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You can't hold it much longer, so you decide to figure out the code as you walk to the bathroom. You picture a keypad
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like this:
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1 2 3
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4 5 6
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7 8 9
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Suppose your instructions are:
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ULL
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RRDDD
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LURDL
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UUUUD
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• You start at "5" and move up (to "2"), left (to "1"), and left (you can't, and stay on "1"), so the first button is
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1.
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• Starting from the previous button ("1"), you move right twice (to "3") and then down three times (stopping at "9"
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after two moves and ignoring the third), ending up with 9.
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• Continuing from "9", you move left, up, right, down, and left, ending with 8.
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• Finally, you move up four times (stopping at "2"), then down once, ending with 5.
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So, in this example, the bathroom code is 1985.
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Your puzzle input is the instructions from the document you found at the front desk. What is the bathroom code?
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Your puzzle answer was 98575.
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--- Part Two ---
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You finally arrive at the bathroom (it's a several minute walk from the lobby so visitors can behold the many fancy
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conference rooms and water coolers on this floor) and go to punch in the code. Much to your bladder's dismay, the
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keypad is not at all like you imagined it. Instead, you are confronted with the result of hundreds of man-hours of
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bathroom-keypad-design meetings:
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1
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2 3 4
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5 6 7 8 9
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A B C
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D
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You still start at "5" and stop when you're at an edge, but given the same instructions as above, the outcome is very
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different:
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• You start at "5" and don't move at all (up and left are both edges), ending at 5.
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• Continuing from "5", you move right twice and down three times (through "6", "7", "B", "D", "D"), ending at D.
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• Then, from "D", you move five more times (through "D", "B", "C", "C", "B"), ending at B.
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• Finally, after five more moves, you end at 3.
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So, given the actual keypad layout, the code would be 5DB3.
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Using the same instructions in your puzzle input, what is the correct bathroom code?
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Your puzzle answer was CD8D4.
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Both parts of this puzzle are complete! They provide two gold stars: **
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At this point, you should return to your advent calendar and try another puzzle.
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If you still want to see it, you can get your puzzle input.
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You can also [Shareon Twitter Google+ Reddit] this puzzle.
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References
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Visible links
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. http://adventofcode.com/
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. http://adventofcode.com/2016/about
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. http://adventofcode.com/2016/support
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. http://adventofcode.com/2016/events
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. http://adventofcode.com/2016/settings
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. http://adventofcode.com/2016/auth/logout
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. http://adventofcode.com/2016
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. http://adventofcode.com/2016
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. http://adventofcode.com/2016/leaderboard
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. http://adventofcode.com/2016/stats
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. http://adventofcode.com/2016/sponsors
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. http://adventofcode.com/2016/sponsors
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. http://adventofcode.com/2016
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. http://adventofcode.com/2016/day/2/input
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. https://twitter.com/intent/tweet?text=I%27ve+completed+%22Bathroom+Security%22+%2D+Day+2+%2D+Advent+of+Code+2016&url=http%3A%2F%2Fadventofcode%2Ecom%2F2016%2Fday%2F2&related=ericwastl&hashtags=AdventOfCode
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. https://plus.google.com/share?url=http%3A%2F%2Fadventofcode%2Ecom%2F2016%2Fday%2F2
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. http://www.reddit.com/submit?url=http%3A%2F%2Fadventofcode%2Ecom%2F2016%2Fday%2F2&title=I%27ve+completed+%22Bathroom+Security%22+%2D+Day+2+%2D+Advent+of+Code+2016
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