commit 6779cfa5c75ac163437cb9a67907825067a42d04
parent 734acf76c6759956e6478d8ed5f089cdb03278a6
Author: Eamon Caddigan <eamon.caddigan@gmail.com>
Date: Tue, 13 Dec 2022 21:48:26 -0800
Solution to day 13, part 1.
Diffstat:
| A | src/day_13.jl | | | 84 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
1 file changed, 84 insertions(+), 0 deletions(-)
diff --git a/src/day_13.jl b/src/day_13.jl
@@ -0,0 +1,84 @@
+# https://adventofcode.com/2022/day/13
+using AdventOfCode
+
+example = readlines(IOBuffer("""
+ [1,1,3,1,1]
+ [1,1,5,1,1]
+
+ [[1],[2,3,4]]
+ [[1],4]
+
+ [9]
+ [[8,7,6]]
+
+ [[4,4],4,4]
+ [[4,4],4,4,4]
+
+ [7,7,7,7]
+ [7,7,7]
+
+ []
+ [3]
+
+ [[[]]]
+ [[]]
+
+ [1,[2,[3,[4,[5,6,7]]]],8,9]
+ [1,[2,[3,[4,[5,6,0]]]],8,9]"""))
+input = readlines("data/day_13.txt")
+
+"""
+Compare packets using AoC day 13 logic.
+"""
+function comparesides(left::Int, right::Int)
+ if left < right
+ "right"
+ elseif left > right
+ "wrong"
+ else
+ "continue"
+ end
+end
+
+function comparesides(left::Vector{<:Any}, right::Vector{<:Any})
+ for i = 1:min(length(left), length(right))
+ i_result = comparesides(left[i], right[i])
+ if i_result != "continue"
+ return i_result
+ end
+ end
+
+ if length(left) < length(right)
+ "right"
+ elseif length(left) > length(right)
+ "wrong"
+ else
+ "continue"
+ end
+end
+
+comparesides(left::Int, right::Vector{<:Any}) = comparesides([left], right)
+
+comparesides(left::Vector{<:Any}, right::Int) = comparesides(left, [right])
+
+"""
+Read the input and return a list of pairs of lists.
+"""
+function parse_input(input)
+ map(
+ (x, y) -> (x, y),
+ map(eval ∘ Meta.parse, input[1:3:end]),
+ map(eval ∘ Meta.parse, input[2:3:end])
+ )
+end
+
+function part_1(input)
+ sum(findall(map(x->comparesides(x[1], x[2]), parse_input(input)) .== "right"))
+end
+@assert part_1(example) == 13
+@info part_1(input)
+
+function part_2(input)
+ nothing
+end
+@info part_2(input)
