Solution to Day 1

src/Year_2025/Julia/Day01/aoc_01.jl

@@ -0,0 +1,74 @@
+#!/usr/bin/env -S julia --project
+module AdventOfCodeDayXX
+    function parse_part1(filename::String)
+        tokens = split(read(filename, String))
+        rotations = Vector{Tuple{Char,Int}}()
+        for t in tokens
+            if isempty(t)
+                continue
+            end
+            push!(rotations, (t[1], parse(Int, t[2:end])))
+        end
+        return rotations
+    end
+
+    function part1(filename::String)
+        rotations = parse_part1(filename)
+        starting = 50
+        counts = 0
+        for (dir, dist) in rotations
+            if dir == 'L'
+                starting = mod(starting - dist, 100)
+            else
+                starting = mod(starting + dist, 100)
+            end
+            if starting == 0
+                counts += 1
+            end
+        end
+        return counts
+    end
+
+    function part2(filename::String)
+        rotations = parse_part1(filename)
+        current = 50
+        counts = 0
+        for (dir, dist) in rotations
+            if dir == 'L'
+                gap = mod(100 - current, 100)
+                wraps = (gap + dist) ÷ 100
+                counts += abs(wraps)
+                current = mod(current - dist, 100)
+            else
+                wraps = (current + dist) ÷ 100
+                counts += abs(wraps)
+                current = mod(current + dist, 100)
+            end
+        end
+        return counts
+    end
+
+    function main()
+        demo_p1 = part1("demo.txt")
+        input_p1 = part1("input.txt")
+        demo_p2 = part2("demo.txt")
+        input_p2 = part2("input.txt")
+
+        println("Advent of Code — Day 01")
+        println("="^23)
+        println("Demo Results:")
+        println("  Part 1: ", demo_p1)
+        println("  Part 2: ", demo_p2)
+        println()
+        println("Input Results:")
+        println("  Part 1: ", input_p1)
+        println("  Part 2: ", input_p2)
+        println("="^23)
+    end
+
+    function __init__()
+        if abspath(PROGRAM_FILE) == @__FILE__
+            main()
+        end
+    end
+end

src/Year_2025/Julia/Day01/demo.txt

@@ -0,0 +1,10 @@
+L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82

src/Year_2025/Julia/template/aoc_xx.jl

@@ -18,10 +18,21 @@ module AdventOfCodeDayXX
     end
 
     function main()
-        @show part1("demo.txt")
-        @show part1("input.txt")
-        @show part2("demo.txt")
-        @show part2("input.txt")
+        demo_p1 = part1("demo.txt")
+        input_p1 = part1("input.txt")
+        demo_p2 = part2("demo.txt")
+        input_p2 = part2("input.txt")
+
+        println("Advent of Code — Day XX")
+        println("="^23)
+        println("Demo Results:")
+        println("  Part 1: ", demo_p1)
+        println("  Part 2: ", demo_p2)
+        println()
+        println("Input Results:")
+        println("  Part 1: ", input_p1)
+        println("  Part 2: ", input_p2)
+        println("="^23)
     end
 
     function __init__()

src/Year_2025/Python/Day01/aoc_01.py

@@ -0,0 +1,40 @@
+with open("input.txt") as f:
+    rotations = [lines for lines in f.read().strip().split()]
+
+starting = 50
+counts = 0
+for rotation in rotations:
+    current = starting
+    direction, distance = rotation[0], int(rotation[1:])
+    if direction == "L":
+        quotient, remainder = divmod(current - distance, 100)
+        starting = remainder
+    else: # "R":
+        quotient, remainder = divmod(current + int(distance), 100)
+        starting = remainder
+    if starting == 0:
+        counts += 1
+
+print(f"There has been {counts} times")
+
+current = 50
+counts = 0
+for rotation in rotations:
+    direction, distance = rotation[0], int(rotation[1:])
+    if direction == "L":
+        # how far you'd have to move forward to reach 0 from current
+        # Example: if current = 30, gap = 70.
+        gap = (100 - current) % 100
+        # If you move left by distance, that is the same as first moving
+        # forward by gap to land on 0, and then continuing forward by
+        # distance more (in that forward-frame of reference). So the total
+        # equivalent forward travel to count wraps is gap + distance
+        quotient, remainder = divmod(gap + distance, 100)
+        current = (current - distance) % 100
+        counts += abs(quotient)
+    else: # "R"
+        quotient, remainder = divmod(current + distance, 100)
+        current = remainder
+        counts += abs(quotient)
+
+print(f"There has been {counts} times, corrected")

src/Year_2025/Python/Day01/demo.txt

@@ -0,0 +1,10 @@
+L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82