franklin-update

posts/adventofcode2024w2.md

@@ -151,6 +151,36 @@ println(sum(pathsp1))
 print(sum(pathsp2))
 ```
 
+## Day 13
+
+Pretty clean solution for Day 13. Don't love the round/asinteger solution but floating point problems were causing headaches.
+
+```julia
+inst = readlines("data/13.txt")
+
+A = [parse.(Int, m.captures) for m in
+     match.(r"A: X\+(\d+), Y\+(\d+)", inst) if !isnothing(m)]
+B = [parse.(Int, m.captures) for m in
+     match.(r"B: X\+(\d+), Y\+(\d+)", inst) if !isnothing(m)]
+P = [parse.(Int, m.captures) for m in
+     match.(r"Prize: X\=(\d+), Y\=(\d+)", inst) if !isnothing(m)]
+
+function solve(adjust=0)
+    ans = 0
+    for i in eachindex(A)
+        sol = hcat(A[i], B[i]) \ (P[i] .+ adjust)
+        if all(isinteger.(round.(sol, digits=3)))
+            ans += sum((3, 1) .* sol)
+        end
+    end
+    return ans
+end
+
+println(solve())
+println(solve(10000000000000))
+```
+
+
 ## Day 14
 
 Solution to part one runs fast, clean solution. Part two requires you to watch a nearly 17 minute long video generated by Makie.jl to find the tree. I'm sure there was a smart way to do this, but when in doubt, look at the data...