2017-12-02

# Day 02: Corruption Checksum

Description:
--- Day 2: Corruption Checksum ---

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!"

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.

For example, given the following spreadsheet:

5 1 9 5
7 5 3
2 4 6 8

The first row's largest and smallest values are 9 and 1, and their difference is 8.
The second row's largest and smallest values are 7 and 3, and their difference is 4.
The third row's difference is 6.

In this example, the spreadsheet's checksum would be 8 + 4 + 6 = 18.

--- Part Two ---

"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?

"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."

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.

For example, given the following spreadsheet:

5 9 2 8
9 4 7 3
3 8 6 5

In the first row, the only two numbers that evenly divide are 8 and 2; the result of this division is 4.
In the second row, the two numbers are 9 and 3; the result is 3.
In the third row, the result is 2.

In this example, the sum of the results would be 4 + 3 + 2 = 9.

What is the sum of each row's result in your puzzle input?

Input:
116 1470 2610 179 2161 2690 831 1824 2361 1050 2201 118 145 2275 2625 2333
976 220 1129 553 422 950 332 204 1247 1092 1091 159 174 182 984 713
84 78 773 62 808 83 1125 1110 1184 145 1277 982 338 1182 75 679
3413 3809 3525 2176 141 1045 2342 2183 157 3960 3084 2643 119 108 3366 2131
1312 205 343 616 300 1098 870 1008 1140 1178 90 146 980 202 190 774
4368 3905 3175 4532 3806 1579 4080 259 2542 221 4395 4464 208 3734 234 4225
741 993 1184 285 1062 372 111 118 63 843 325 132 854 105 956 961
85 79 84 2483 858 2209 2268 90 2233 1230 2533 322 338 68 2085 1267
2688 2022 112 130 1185 103 1847 3059 911 107 2066 1788 2687 2633 415 1353
76 169 141 58 161 66 65 225 60 152 62 64 156 199 80 56
220 884 1890 597 3312 593 4259 222 113 2244 3798 4757 216 1127 4400 178
653 369 216 132 276 102 265 889 987 236 239 807 1076 932 84 864
799 739 75 1537 82 228 69 1397 1396 1203 1587 63 313 1718 1375 469
1176 112 1407 136 1482 1534 1384 1202 604 851 190 284 1226 113 114 687
73 1620 81 1137 812 75 1326 1355 1545 1666 1356 1681 1732 85 128 902
571 547 160 237 256 30 496 592 385 576 183 692 192 387 647 233

Part 1:
``````#!/usr/bin/env python3

import aoc

result = 0
for line in rawinput.splitlines():
values = list(map(lambda d: int(d), line.split('\t')))
result = result + (max(values) - min(values))

print(result)
``````
Result: 32020

Part 2:
``````#!/usr/bin/env python3

import aoc

result = 0
for line in rawinput.splitlines():
values = list(map(lambda d: int(d), line.split('\t')))
for v1 in values:
for v2 in values:
if v1 == v2:
continue
if v1 % v2 == 0:
result = result + v1//v2

print(result)
``````
Result: 236

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