2018-12-14 18:58:05 +00:00
|
|
|
|
Advent of Code
|
|
|
|
|
|
|
|
|
|
|
|
--- Day 14: Chocolate Charts ---
|
|
|
|
|
|
|
2019-11-08 21:01:07 +00:00
|
|
|
|
You finally have a chance to look at all of the produce moving around.
|
|
|
|
|
|
Chocolate, cinnamon, mint, chili peppers, nutmeg, vanilla... the Elves must
|
|
|
|
|
|
be growing these plants to make hot chocolate! As you realize this, you hear
|
|
|
|
|
|
a conversation in the distance. When you go to investigate, you discover two
|
|
|
|
|
|
Elves in what appears to be a makeshift underground kitchen/laboratory.
|
|
|
|
|
|
|
|
|
|
|
|
The Elves are trying to come up with the ultimate hot chocolate recipe;
|
|
|
|
|
|
they're even maintaining a scoreboard which tracks the quality score (0-9)
|
|
|
|
|
|
of each recipe.
|
|
|
|
|
|
|
|
|
|
|
|
Only two recipes are on the board: the first recipe got a score of 3, the
|
|
|
|
|
|
second, 7. Each of the two Elves has a current recipe: the first Elf starts
|
|
|
|
|
|
with the first recipe, and the second Elf starts with the second recipe.
|
|
|
|
|
|
|
|
|
|
|
|
To create new recipes, the two Elves combine their current recipes. This
|
|
|
|
|
|
creates new recipes from the digits of the sum of the current recipes'
|
|
|
|
|
|
scores. With the current recipes' scores of 3 and 7, their sum is 10, and so
|
|
|
|
|
|
two new recipes would be created: the first with score 1 and the second with
|
|
|
|
|
|
score 0. If the current recipes' scores were 2 and 3, the sum, 5, would only
|
|
|
|
|
|
create one recipe (with a score of 5) with its single digit.
|
|
|
|
|
|
|
|
|
|
|
|
The new recipes are added to the end of the scoreboard in the order they are
|
|
|
|
|
|
created. So, after the first round, the scoreboard is 3, 7, 1, 0.
|
|
|
|
|
|
|
|
|
|
|
|
After all new recipes are added to the scoreboard, each Elf picks a new
|
|
|
|
|
|
current recipe. To do this, the Elf steps forward through the scoreboard a
|
|
|
|
|
|
number of recipes equal to 1 plus the score of their current recipe. So,
|
|
|
|
|
|
after the first round, the first Elf moves forward 1 + 3 = 4 times, while
|
|
|
|
|
|
the second Elf moves forward 1 + 7 = 8 times. If they run out of recipes,
|
|
|
|
|
|
they loop back around to the beginning. After the first round, both Elves
|
|
|
|
|
|
happen to loop around until they land on the same recipe that they had in
|
|
|
|
|
|
the beginning; in general, they will move to different recipes.
|
|
|
|
|
|
|
|
|
|
|
|
Drawing the first Elf as parentheses and the second Elf as square brackets,
|
|
|
|
|
|
they continue this process:
|
|
|
|
|
|
|
|
|
|
|
|
(3)[7] (3)[7] 1 0 3 7 1 [0](1) 0 3 7 1 0 [1] 0 (1) (3) 7 1 0 1 0 [1]
|
|
|
|
|
|
2 3 7 1 0 (1) 0 1 2 [4] 3 7 1 [0] 1 0 (1) 2 4 5 3 7 1 0 [1] 0 1
|
|
|
|
|
|
2 (4) 5 1 3 (7) 1 0 1 0 [1] 2 4 5 1 5 3 7 1 0 1 0 1 2 [4](5) 1
|
|
|
|
|
|
5 8 3 (7) 1 0 1 0 1 2 4 5 1 5 8 [9] 3 7 1 0 1 0 1 [2] 4 (5) 1
|
|
|
|
|
|
5 8 9 1 6 3 7 1 0 1 0 1 2 4 5 [1] 5 8 9 1 (6) 7 3 7 1 0 (1)
|
|
|
|
|
|
0 1 2 4 5 1 5 [8] 9 1 6 7 7 3 7 [1] 0 1 0 (1) 2 4 5 1 5 8 9
|
|
|
|
|
|
1 6 7 7 9 3 7 1 0 [1] 0 1 2 (4) 5 1 5 8 9 1 6 7 7 9 2
|
|
|
|
|
|
|
|
|
|
|
|
The Elves think their skill will improve after making a few recipes (your
|
|
|
|
|
|
puzzle input). However, that could take ages; you can speed this up
|
|
|
|
|
|
considerably by identifying the scores of the ten recipes after that. For
|
2018-12-14 18:58:05 +00:00
|
|
|
|
example:
|
|
|
|
|
|
|
2019-11-08 21:01:07 +00:00
|
|
|
|
• If the Elves think their skill will improve after making 9 recipes, the
|
|
|
|
|
|
scores of the ten recipes after the first nine on the scoreboard would be
|
|
|
|
|
|
5158916779 (highlighted in the last line of the diagram). • After 5
|
|
|
|
|
|
recipes, the scores of the next ten would be 0124515891. • After 18
|
|
|
|
|
|
recipes, the scores of the next ten would be 9251071085. • After 2018
|
|
|
|
|
|
recipes, the scores of the next ten would be 5941429882.
|
2018-12-14 18:58:05 +00:00
|
|
|
|
|
2019-11-08 21:01:07 +00:00
|
|
|
|
What are the scores of the ten recipes immediately after the number of
|
|
|
|
|
|
recipes in your puzzle input?
|
2018-12-14 18:58:05 +00:00
|
|
|
|
|
|
|
|
|
|
Your puzzle answer was 1776718175.
|
|
|
|
|
|
|
|
|
|
|
|
--- Part Two ---
|
|
|
|
|
|
|
2019-11-08 21:01:07 +00:00
|
|
|
|
As it turns out, you got the Elves' plan backwards. They actually want to
|
|
|
|
|
|
know how many recipes appear on the scoreboard to the left of the first
|
|
|
|
|
|
recipes whose scores are the digits from your puzzle input.
|
2018-12-14 18:58:05 +00:00
|
|
|
|
|
2019-11-08 21:01:07 +00:00
|
|
|
|
• 51589 first appears after 9 recipes. • 01245 first appears after 5
|
|
|
|
|
|
recipes. • 92510 first appears after 18 recipes. • 59414 first appears
|
|
|
|
|
|
after 2018 recipes.
|
2018-12-14 18:58:05 +00:00
|
|
|
|
|
2019-11-08 21:01:07 +00:00
|
|
|
|
How many recipes appear on the scoreboard to the left of the score sequence
|
|
|
|
|
|
in your puzzle input?
|
2018-12-14 18:58:05 +00:00
|
|
|
|
|
|
|
|
|
|
Your puzzle answer was 20220949.
|
|
|
|
|
|
|
|
|
|
|
|
Both parts of this puzzle are complete! They provide two gold stars: **
|
|
|
|
|
|
|
|
|
|
|
|
Your puzzle input was 290431.
|
|
|
|
|
|
|
|
|
|
|
|
References
|
|
|
|
|
|
|
|
|
|
|
|
Visible links
|
|
|
|
|
|
. https://adventofcode.com/
|
|
|
|
|
|
. https://adventofcode.com/2018/about
|
|
|
|
|
|
. https://adventofcode.com/2018/events
|
|
|
|
|
|
. https://adventofcode.com/2018/settings
|
|
|
|
|
|
. https://adventofcode.com/2018/auth/logout
|
|
|
|
|
|
. Advent of Code Supporter
|
|
|
|
|
|
https://adventofcode.com/2018/support
|
|
|
|
|
|
. https://adventofcode.com/2018
|
|
|
|
|
|
. https://adventofcode.com/2018
|
|
|
|
|
|
. https://adventofcode.com/2018/support
|
|
|
|
|
|
. https://adventofcode.com/2018/sponsors
|
|
|
|
|
|
. https://adventofcode.com/2018/leaderboard
|
|
|
|
|
|
. https://adventofcode.com/2018/stats
|
|
|
|
|
|
. https://adventofcode.com/2018/sponsors
|
|
|
|
|
|
. https://adventofcode.com/2018
|
