commit 16930c5f191badf4725c261a4536b36c2ae1587b
parent 89f1b4cc16176e9af1cd4d636565aeee754a76ae
Author: Eamon Caddigan <eamon.caddigan@gmail.com>
Date: Sun, 4 Dec 2022 06:47:39 -0800
Solution to day 4 (both parts).
Didn't feel like it was worth splittig into two commits.
Diffstat:
| A | src/day_4.jl | | | 44 | ++++++++++++++++++++++++++++++++++++++++++++ |
1 file changed, 44 insertions(+), 0 deletions(-)
diff --git a/src/day_4.jl b/src/day_4.jl
@@ -0,0 +1,44 @@
+#!/usr/bin/env julia
+# https://adventofcode.com/2022/day/4
+using AdventOfCode
+
+example = split("""
+ 2-4,6-8
+ 2-3,4-5
+ 5-7,7-9
+ 2-8,3-7
+ 6-6,4-6
+ 2-6,4-8""",
+ "\n")
+input = readlines("data/day_4.txt")
+
+# Split an input line into an array of arrays
+function parse_line(inputline::AbstractString)
+ map(x->parse.(Int, split(x, "-")), split(inputline, ","))
+end
+
+# Return true iff one assignment range is entirely contained in another
+function check_containment(assignments::Array{Array{Int,1},1})
+ (assignments[1][1] >= assignments[2][1] && assignments[1][2] <= assignments[2][2]) ||
+ (assignments[2][1] >= assignments[1][1] && assignments[2][2] <= assignments[1][2])
+end
+
+function part_1(input::Array{<:AbstractString,1})
+ sum(map(check_containment, map(parse_line, input)))
+end
+@assert part_1(example) == 2
+@info part_1(input)
+
+# For part 2 I'm simply checking if assignments overlap at all. Not too hard
+
+# Return true iff the assignments overlap at all
+function check_overlap(assignments::Array{Array{Int,1},1})
+ assignments[1][1] <= assignments[2][2] &&
+ assignments[1][2] >= assignments[2][1]
+end
+
+function part_2(input::Array{<:AbstractString,1})
+ sum(map(check_overlap, map(parse_line, input)))
+end
+@assert part_2(example) == 4
+@info part_2(input)
