44 lines
1.6 KiB
Org Mode
44 lines
1.6 KiB
Org Mode
* --- Day 1: The Tyranny of the Rocket Equation ---
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:PROPERTIES:
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:CUSTOM_ID: day-1-the-tyranny-of-the-rocket-equation----
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:END:
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Santa has become stranded at the edge of the Solar System while
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delivering presents to other planets! To accurately calculate his
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position in space, safely align his warp drive, and return to Earth in
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time to save Christmas, he needs you to bring him measurements from
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/fifty stars/.
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Collect stars by solving puzzles. Two puzzles will be made available on
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each day in the Advent calendar; the second puzzle is unlocked when you
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complete the first. Each puzzle grants /one star/. Good luck!
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The Elves quickly load you into a spacecraft and prepare to launch.
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At the first Go / No Go poll, every Elf is Go until the Fuel
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Counter-Upper. They haven't determined the amount of fuel required yet.
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Fuel required to launch a given /module/ is based on its /mass/.
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Specifically, to find the fuel required for a module, take its mass,
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divide by three, round down, and subtract 2.
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For example:
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- For a mass of =12=, divide by 3 and round down to get =4=, then
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subtract 2 to get =2=.
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- For a mass of =14=, dividing by 3 and rounding down still yields =4=,
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so the fuel required is also =2=.
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- For a mass of =1969=, the fuel required is =654=.
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- For a mass of =100756=, the fuel required is =33583=.
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The Fuel Counter-Upper needs to know the total fuel requirement. To find
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it, individually calculate the fuel needed for the mass of each module
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(your puzzle input), then add together all the fuel values.
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/What is the sum of the fuel requirements/ for all of the modules on
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your spacecraft?
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To begin, [[file:1/input][get your puzzle input]].
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Answer:
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