76 lines
3.1 KiB
Plaintext
76 lines
3.1 KiB
Plaintext
Advent of Code
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br0xen 40*
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• [About]
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• [Stats]
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• [Leaderboard]
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• [Settings]
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• [Log out]
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--- Day 3: Perfectly Spherical Houses in a Vacuum ---
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Santa is delivering presents to an infinite two-dimensional grid of houses.
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He begins by delivering a present to the house at his starting location, and then an elf at the
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North Pole calls him via radio and tells him where to move next. Moves are always exactly one
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house to the north (^), south (v), east (>), or west (<). After each move, he delivers another
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present to the house at his new location.
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However, the elf back at the north pole has had a little too much eggnog, and so his directions
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are a little off, and Santa ends up visiting some houses more than once. How many houses
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receive at least one present?
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For example:
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• > delivers presents to 2 houses: one at the starting location, and one to the east.
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• ^>v< delivers presents to 4 houses in a square, including twice to the house at his
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starting/ending location.
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• ^v^v^v^v^v delivers a bunch of presents to some very lucky children at only 2 houses.
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Your puzzle answer was 2572.
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--- Part Two ---
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The next year, to speed up the process, Santa creates a robot version of himself, Robo-Santa,
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to deliver presents with him.
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Santa and Robo-Santa start at the same location (delivering two presents to the same starting
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house), then take turns moving based on instructions from the elf, who is eggnoggedly reading
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from the same script as the previous year.
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This year, how many houses receive at least one present?
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For example:
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• ^v delivers presents to 3 houses, because Santa goes north, and then Robo-Santa goes south.
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• ^>v< now delivers presents to 3 houses, and Santa and Robo-Santa end up back where they
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started.
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• ^v^v^v^v^v now delivers presents to 11 houses, with Santa going one direction and
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Robo-Santa going the other.
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Your puzzle answer was 2631.
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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/about
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. http://adventofcode.com/stats
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. http://adventofcode.com/leaderboard
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. http://adventofcode.com/settings
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. http://adventofcode.com/auth/logout
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. http://adventofcode.com/
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. http://adventofcode.com/day/3/input
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. https://twitter.com/intent/tweet?text=I%27ve+completed+%22Perfectly+Spherical+Houses+in+a+Vacuum%22+%2D+Day+3+%2D+Advent+of+Code&url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F3&related=ericwastl&hashtags=AdventOfCode
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. https://plus.google.com/share?url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F3
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. http://www.reddit.com/submit?url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F3&title=I%27ve+completed+%22Perfectly+Spherical+Houses+in+a+Vacuum%22+%2D+Day+3+%2D+Advent+of+Code
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