2.0 KiB
--- Day 8: I Heard You Like Registers ---
You receive a signal directly from the CPU. Because of your recent assistance with jump instructions, it would like you to compute the result of a series of unusual register instructions.
Each instruction consists of several parts: the register to modify,
whether to increase or decrease that register's value, the amount by
which to increase or decrease it, and a condition. If the condition
fails, skip the instruction without modifying the register. The
registers all start at 0
. The instructions look like this:
b inc 5 if a > 1
a inc 1 if b < 5
c dec -10 if a >= 1
c inc -20 if c == 10
These instructions would be processed as follows:
- Because
a
starts at0
, it is not greater than1
, and sob
is not modified. a
is increased by1
(to1
) becauseb
is less than5
(it is0
).c
is decreased by-10
(to10
) becausea
is now greater than or equal to1
(it is1
).c
is increased by-20
(to-10
) becausec
is equal to10
.
After this process, the largest value in any register is 1
.
You might also encounter <=
(less than or equal to) or !=
(not equal
to). However, the CPU doesn't have the bandwidth to tell you what all
the registers are named, and leaves that to you to determine.
What is the largest value in any register after completing the instructions in your puzzle input?
Your puzzle answer was 4066
.
--- Part Two ---
To be safe, the CPU also needs to know the highest value held in any
register during this process so that it can decide how much memory to
allocate to these operations. For example, in the above instructions,
the highest value ever held was 10
(in register c
after the third
instruction was evaluated).
Your puzzle answer was 4829
.
Both parts of this puzzle are complete! They provide two gold stars: **
At this point, you should return to your Advent calendar and try another puzzle.
If you still want to see it, you can get your puzzle input.