57 lines
2.5 KiB
Text
57 lines
2.5 KiB
Text
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\--- Day 2: Corruption Checksum ---
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----------
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As you walk through the door, a glowing humanoid shape yells in your direction. "You there! Your state appears to be idle. Come help us repair the corruption in this spreadsheet - if we take another millisecond, we'll have to display an hourglass cursor!"
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The spreadsheet consists of rows of apparently-random numbers. To make sure the recovery process is on the right track, they need you to calculate the spreadsheet's *checksum*. For each row, determine the difference between the largest value and the smallest value; the checksum is the sum of all of these differences.
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For example, given the following spreadsheet:
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```
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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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```
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* The first row's largest and smallest values are `9` and `1`, and their difference is `8`.
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* The second row's largest and smallest values are `7` and `3`, and their 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 `45972`.
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\--- Part Two ---
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----------
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"Great work; looks like we're on the right track after all. Here's a *star* for your effort." However, the program seems a little worried. Can programs *be* worried?
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"Based on what we're seeing, it looks like all the User wanted is some information about the *evenly divisible values* in the spreadsheet. Unfortunately, none of us are equipped for that kind of calculation - most of 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 evenly divides the other - that is, where the result of the division operation is a whole number. They would like you to find those numbers on 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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```
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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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```
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* In the first row, the only two numbers that evenly divide are `8` and `2`; 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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Your puzzle answer was `326`.
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Both parts of this puzzle are complete! They provide two gold stars: \*\*
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At this point, all that is left is for you to [admire your Advent calendar](/2017).
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If you still want to see it, you can [get your puzzle input](2/input).
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