75 lines
2.4 KiB
Org Mode
75 lines
2.4 KiB
Org Mode
** --- Day 4: Camp Cleanup ---
|
|
Space needs to be cleared before the last supplies can be unloaded from
|
|
the ships, and so several Elves have been assigned the job of cleaning
|
|
up sections of the camp. Every section has a unique /ID number/, and
|
|
each Elf is assigned a range of section IDs.
|
|
|
|
However, as some of the Elves compare their section assignments with
|
|
each other, they've noticed that many of the assignments /overlap/. To
|
|
try to quickly find overlaps and reduce duplicated effort, the Elves
|
|
pair up and make a /big list of the section assignments for each pair/
|
|
(your puzzle input).
|
|
|
|
For example, consider the following list of section assignment pairs:
|
|
|
|
#+begin_example
|
|
2-4,6-8
|
|
2-3,4-5
|
|
5-7,7-9
|
|
2-8,3-7
|
|
6-6,4-6
|
|
2-6,4-8
|
|
#+end_example
|
|
|
|
For the first few pairs, this list means:
|
|
|
|
- Within the first pair of Elves, the first Elf was assigned sections
|
|
=2-4= (sections =2=, =3=, and =4=), while the second Elf was assigned
|
|
sections =6-8= (sections =6=, =7=, =8=).
|
|
- The Elves in the second pair were each assigned two sections.
|
|
- The Elves in the third pair were each assigned three sections: one got
|
|
sections =5=, =6=, and =7=, while the other also got =7=, plus =8= and
|
|
=9=.
|
|
|
|
This example list uses single-digit section IDs to make it easier to
|
|
draw; your actual list might contain larger numbers. Visually, these
|
|
pairs of section assignments look like this:
|
|
|
|
#+begin_example
|
|
.234..... 2-4
|
|
.....678. 6-8
|
|
|
|
.23...... 2-3
|
|
...45.... 4-5
|
|
|
|
....567.. 5-7
|
|
......789 7-9
|
|
|
|
.2345678. 2-8
|
|
..34567.. 3-7
|
|
|
|
.....6... 6-6
|
|
...456... 4-6
|
|
|
|
.23456... 2-6
|
|
...45678. 4-8
|
|
#+end_example
|
|
|
|
Some of the pairs have noticed that one of their assignments /fully
|
|
contains/ the other. For example, =2-8= fully contains =3-7=, and =6-6=
|
|
is fully contained by =4-6=. In pairs where one assignment fully
|
|
contains the other, one Elf in the pair would be exclusively cleaning
|
|
sections their partner will already be cleaning, so these seem like the
|
|
most in need of reconsideration. In this example, there are =2= such
|
|
pairs.
|
|
|
|
/In how many assignment pairs does one range fully contain the other?/
|
|
|
|
To begin, [[file:4/input][get your puzzle input]].
|
|
|
|
Answer:
|
|
|
|
You can also [Shareon
|
|
[[https://twitter.com/intent/tweet?text=%22Camp+Cleanup%22+%2D+Day+4+%2D+Advent+of+Code+2022&url=https%3A%2F%2Fadventofcode%2Ecom%2F2022%2Fday%2F4&related=ericwastl&hashtags=AdventOfCode][Twitter]]
|
|
[[javascript:void(0);][Mastodon]]] this puzzle.
|