Add solution for day 7

solutions/2024/src/AdventOfCode24.jl

@@ -8,7 +8,7 @@ module AdventOfCode24
     readInput(day::Int) = AdventOfCode.readInput(day, year)
     export readInput
 
-    solvedDays = [1, 2, 3, 4, 5, 6]
+    solvedDays = [1, 2, 3, 4, 5, 6, 7]
 
     # Include the source files:
     for day in solvedDays

solutions/2024/src/day07.jl

@@ -0,0 +1,63 @@
+module Day07
+    using ..AdventOfCode24
+
+    """
+        day07()
+
+    Solves the two puzzles of day 07. 
+    """
+
+    function day07(input::String = readInput(07))
+        lines = split(input, "\n")
+
+        s0 = 0
+        s1 = 0
+
+        for l in lines
+            res = parse(Int, match(r"(\d+):", l).captures[1])
+            args = [parse.(Int, m.captures[1]) for m in eachmatch(r"\s(\d+)", l)]
+
+            if is_valid(res, args)
+                s0 += res
+                s1 += res
+            elseif is_valid(res, args, true)
+                s1 += res
+            end
+
+        end
+
+        return [s0, s1]
+    end
+
+    function |(l::Int, r::Int)
+        return l * 10^(floor(Int,log10(r))+1)  + r
+    end
+
+    function is_valid(res::Int, args::Vector{Int}, concat::Bool=false)
+
+        stack = [(args[1], args[2], 2, +),
+                    (args[1], args[2], 2, *)]
+
+        concat && push!(stack, (args[1], args[2], 2, |))
+
+        while !isempty(stack)
+            l, r, i, op = pop!(stack)
+            ans = op(l, r)
+
+            if res == ans && i == length(args)
+                return true
+            elseif res < ans || i == length(args)
+                continue
+            else
+                push!(stack, (ans, args[i+1], i+1, +))
+                push!(stack, (ans, args[i+1], i+1, *))
+                concat && push!(stack, (ans, args[i+1], i+1, |))
+            end
+        end
+
+        return false
+
+    end
+
+
+end 

solutions/2024/test/runtests.jl

@@ -20,5 +20,9 @@ end
     @test AdventOfCode24.Day05.day05() == [5651, 4743]
 end
 @testset "Day 06" begin
-    @test AdventOfCode24.Day06.day06() == [s0, s1]
+    @test AdventOfCode24.Day06.day06() == [5531, 2165]
+end
+
+@testset "Day 07" begin
+    @test AdventOfCode24.Day07.day07() == [975671981569, 223472064194845]
 end