Day 01

src/Year_2024/Day_01.jl

@@ -0,0 +1,41 @@
+using BenchmarkTools
+using StatsBase
+
+function Day_01()
+    # Robust file reading and parsing
+    list_nums = Vector{Int}()
+    open("files/P1.txt", "r") do file
+        for line in eachline(file)
+            # Split the line and parse the first two numbers
+            nums = split(strip(line))
+            if length(nums) >= 2
+                push!(list_nums, parse(Int, nums[1]))
+                push!(list_nums, parse(Int, nums[2]))
+            end
+        end
+    end
+
+    # Preallocate arrays and use views to avoid unnecessary allocations
+    l1 = view(list_nums, 1:2:length(list_nums))
+    l2 = view(list_nums, 2:2:length(list_nums))
+
+    # Sort in-place to reduce memory allocations
+    sort!(l1)
+    sort!(l2)
+
+    # Optimized part 1: Use broadcast with a temporary array to avoid repeated allocations
+    p1 = sum(abs, l1 .- l2)
+
+    # Optimized part 2: Use dictionary for efficient counting and avoid multiple passes
+    freq = Dict{Int, Int}()
+    for x in l2
+        freq[x] = get(freq, x, 0) + 1
+    end
+
+    p2 = sum(x -> x * get(freq, x, 0), l1)
+
+    return p1, p2
+end
+
+println(Day_01())
+@btime Day_01()