76 lines
2.7 KiB
Plaintext
76 lines
2.7 KiB
Plaintext
Advent of Code
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--- Day 2: I Was Told There Would Be No Math ---
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The elves are running low on wrapping paper, and so they need to submit an
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order for more. They have a list of the dimensions (length l, width w, and
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height h) of each present, and only want to order exactly as much as they
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need.
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Fortunately, every present is a box (a perfect right rectangular prism),
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which makes calculating the required wrapping paper for each gift a little
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easier: find the surface area of the box, which is 2*l*w + 2*w*h + 2*h*l.
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The elves also need a little extra paper for each present: the area of the
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smallest side.
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For example:
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• A present with dimensions 2x3x4 requires 2*6 + 2*12 + 2*8 = 52 square
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feet of wrapping paper plus 6 square feet of slack, for a total of 58
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square feet.
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• A present with dimensions 1x1x10 requires 2*1 + 2*10 + 2*10 = 42 square
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feet of wrapping paper plus 1 square foot of slack, for a total of 43
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square feet.
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All numbers in the elves' list are in feet. How many total square feet of
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wrapping paper should they order?
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Your puzzle answer was 1588178.
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--- Part Two ---
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The elves are also running low on ribbon. Ribbon is all the same width, so
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they only have to worry about the length they need to order, which they
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would again like to be exact.
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The ribbon required to wrap a present is the shortest distance around its
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sides, or the smallest perimeter of any one face. Each present also requires
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a bow made out of ribbon as well; the feet of ribbon required for the
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perfect bow is equal to the cubic feet of volume of the present. Don't ask
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how they tie the bow, though; they'll never tell.
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For example:
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• A present with dimensions 2x3x4 requires 2+2+3+3 = 10 feet of ribbon to
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wrap the present plus 2*3*4 = 24 feet of ribbon for the bow, for a total
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of 34 feet.
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• A present with dimensions 1x1x10 requires 1+1+1+1 = 4 feet of ribbon to
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wrap the present plus 1*1*10 = 10 feet of ribbon for the bow, for a total
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of 14 feet.
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How many total feet of ribbon should they order?
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Your puzzle answer was 3783758.
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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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. https://en.wikipedia.org/wiki/Cuboid#Rectangular_cuboid
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. http://adventofcode.com/
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. http://adventofcode.com/day/2/input
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