73 lines
2.4 KiB
Plaintext
73 lines
2.4 KiB
Plaintext
Advent of Code
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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
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then an elf at the North Pole calls him via radio and tells him where to
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move next. Moves are always exactly one house to the north (^), south (v),
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east (>), or west (<). After each move, he delivers another present to the
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house at his new location.
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However, the elf back at the north pole has had a little too much eggnog,
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and so his directions are a little off, and Santa ends up visiting some
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houses more than once. How many houses 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
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to the east.
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• ^>v< delivers presents to 4 houses in a square, including twice to the
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house at his starting/ending location.
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• ^v^v^v^v^v delivers a bunch of presents to some very lucky children at
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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
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himself, Robo-Santa, to deliver presents with him.
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Santa and Robo-Santa start at the same location (delivering two presents to
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the same starting house), then take turns moving based on instructions from
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the elf, who is eggnoggedly reading from the same script as the previous
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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
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Robo-Santa goes south.
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• ^>v< now delivers presents to 3 houses, and Santa and Robo-Santa end up
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back where they started.
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• ^v^v^v^v^v now delivers presents to 11 houses, with Santa going one
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direction and 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
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puzzle.
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If you still want to see it, you can get your puzzle input.
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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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