89 lines
3.1 KiB
Plaintext
89 lines
3.1 KiB
Plaintext
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Advent of Code
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--- Day 2: Corruption Checksum ---
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As you walk through the door, a glowing humanoid shape yells in your
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direction. "You there! Your state appears to be idle. Come help us repair the
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corruption in this spreadsheet - if we take another millisecond, we'll have
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to display an hourglass cursor!"
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The spreadsheet consists of rows of apparently-random numbers. To make sure
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the recovery process is on the right track, they need you to calculate the
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spreadsheet's checksum. For each row, determine the difference between the
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largest value and the smallest value; the checksum is the sum of all of these
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differences.
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For example, given the following spreadsheet:
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5 1 9 5
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7 5 3
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2 4 6 8
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* The first row's largest and smallest values are 9 and 1, and their
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difference is 8.
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* The second row's largest and smallest values are 7 and 3, and their
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difference is 4.
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* The third row's difference is 6.
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In this example, the spreadsheet's checksum would be 8 + 4 + 6 = 18.
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What is the checksum for the spreadsheet in your puzzle input?
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Your puzzle answer was ____.
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The first half of this puzzle is complete! It provides one gold star: *
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--- Part Two ---
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"Great work; looks like we're on the right track after all. Here's a star for
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your effort." However, the program seems a little worried. Can programs be
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worried?
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"Based on what we're seeing, it looks like all the User wanted is some
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information about the evenly divisible values in the spreadsheet.
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Unfortunately, none of us are equipped for that kind of calculation - most of
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us specialize in bitwise operations."
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It sounds like the goal is to find the only two numbers in each row where one
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evenly divides the other - that is, where the result of the division
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operation is a whole number. They would like you to find those numbers on
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each line, divide them, and add up each line's result.
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For example, given the following spreadsheet:
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5 9 2 8
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9 4 7 3
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3 8 6 5
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* In the first row, the only two numbers that evenly divide are 8 and 2;
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the result of this division is 4.
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* In the second row, the two numbers are 9 and 3; the result is 3.
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* In the third row, the result is 2.
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In this example, the sum of the results would be 4 + 3 + 2 = 9.
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What is the sum of each row's result in your puzzle input?
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Although it hasn't changed, you can still get your puzzle input.
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Answer: _____________________
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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/2017/about
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. http://adventofcode.com/2017/support
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. http://adventofcode.com/2017/events
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. http://adventofcode.com/2017/settings
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. http://adventofcode.com/2017/auth/logout
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. http://adventofcode.com/2017
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. http://adventofcode.com/2017
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. http://adventofcode.com/2017/leaderboard
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. http://adventofcode.com/2017/stats
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. http://adventofcode.com/2017/sponsors
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. http://adventofcode.com/2017/sponsors
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. http://adventofcode.com/2017/day/2/input
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