Day 1: the camel

.gitignore

@@ -1,2 +1,4 @@
 ./zig-out
 ./zig-cache
+_build
+input.txt

AdventOfCode2024/AdventOfCode2024.opam

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+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis: "A short synopsis"
+description: "A longer description"
+maintainer: ["Maintainer Name"]
+authors: ["Author Name"]
+license: "LICENSE"
+tags: ["topics" "to describe" "your" "project"]
+homepage: "https://github.com/username/reponame"
+doc: "https://url/to/documentation"
+bug-reports: "https://github.com/username/reponame/issues"
+depends: [
+  "ocaml"
+  "dune" {>= "3.16"}
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/username/reponame.git"

AdventOfCode2024/bin/dune

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+(executable
+ (public_name AdventOfCode2024)
+ (name main)
+ (libraries AdventOfCode2024))

AdventOfCode2024/bin/main.ml

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+open Scanf
+
+let read_lines name =
+  let ic = open_in name in
+  let try_read () =
+    try Some (input_line ic) with End_of_file -> None in
+  let rec loop acc = match try_read () with
+    | Some s -> loop (s :: acc)
+    | None -> close_in ic; List.rev acc in
+  loop []
+
+let handle_line line =
+    sscanf line "%d   %d" (fun num1 num2 -> (num1, num2))
+
+let sort_list l =
+    List.sort compare l
+
+let build_lists lines =
+    let rec loop lines l1 l2 = match lines with
+        | [] -> (l1, l2)
+        | head :: tail -> 
+            let (num1, num2) = handle_line head in
+            loop tail (l1 @ [num1]) (l2 @ [num2]) in
+    loop lines [] [] |> (fun (l1, l2) -> (sort_list l1, sort_list l2))
+
+let find_occurances l item =
+    let rec loop l item acc = match l with
+        | [] -> acc
+        | head :: tail -> if head == item then loop tail item (acc + 1) else loop tail item acc in
+    loop l item 0
+
+let () = 
+    print_endline "\nAdvent of Code 2024";
+    let lines = read_lines "./bin/input.txt" in
+
+    let rec distance l1 l2 acc =
+        match (l1, l2) with
+            | ([], []) -> acc
+            | (h1 :: t1, h2 :: t2) ->
+                distance t1 t2 (acc + if h1 > h2 then h1 - h2 else h2 - h1)
+            | _, _ -> acc in
+
+    let (l1, l2) = build_lists lines in
+    let part1 = distance l1 l2 0 in
+    Printf.printf "Part 1: %s\n" (string_of_int part1);
+
+    let rec similarity l1 l2 acc =
+        match l1 with
+            | [] -> acc
+            | head :: tail -> similarity tail l2 (acc + head * find_occurances l2 head) in
+    
+    let part2 = similarity l1 l2 0 in
+    Printf.printf "Part 2: %s\n" (string_of_int part2);

AdventOfCode2024/dune-project

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+(lang dune 3.16)
+
+(name AdventOfCode2024)
+
+(generate_opam_files true)
+
+(source
+ (github username/reponame))
+
+(authors "Author Name")
+
+(maintainers "Maintainer Name")
+
+(license LICENSE)
+
+(documentation https://url/to/documentation)
+
+(package
+ (name AdventOfCode2024)
+ (synopsis "A short synopsis")
+ (description "A longer description")
+ (depends ocaml dune)
+ (tags
+  (topics "to describe" your project)))
+
+; See the complete stanza docs at https://dune.readthedocs.io/en/stable/reference/dune-project/index.html

AdventOfCode2024/lib/dune

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+(library
+ (name AdventOfCode2024))

AdventOfCode2024/test/dune

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+(test
+ (name test_AdventOfCode2024))