From 6e927cd05b99848f3cd9c9edf8bc125538515423 Mon Sep 17 00:00:00 2001
From: John Costa <johncosta027@gmail.com>
Date: Mon, 2 Dec 2024 18:33:37 +0000
Subject: [PATCH] feat: day2
---
AdventOfCode2024/bin/main.ml | 2 +-
AdventOfCode2024/lib/day_02.ml | 76 ++++++++++++++++++++++++++++++++++
2 files changed, 77 insertions(+), 1 deletion(-)
create mode 100644 AdventOfCode2024/lib/day_02.ml
diff --git a/AdventOfCode2024/bin/main.ml b/AdventOfCode2024/bin/main.ml
index 9687989..d617642 100644
--- a/AdventOfCode2024/bin/main.ml
+++ b/AdventOfCode2024/bin/main.ml
@@ -13,7 +13,7 @@ let read_lines name =
let () =
print_endline "\nAdvent of Code 2024";
let part1, part2 =
- read_lines "./inputs/01.txt" |> AdventOfCode2024.Day_01.solve
+ read_lines "./inputs/02.txt" |> AdventOfCode2024.Day_02.solve
in
Printf.printf "Part 1: %s\nPart 2: %s\n" (string_of_int part1)
(string_of_int part2)
diff --git a/AdventOfCode2024/lib/day_02.ml b/AdventOfCode2024/lib/day_02.ml
new file mode 100644
index 0000000..39fdfa3
--- /dev/null
+++ b/AdventOfCode2024/lib/day_02.ml
@@ -0,0 +1,76 @@
+open Scanf
+
+let handle_line line = sscanf line "%d %d" (fun num1 num2 -> (num1, num2))
+let sort_list l = List.sort compare l
+let print_list l = List.iter (Printf.printf "%d ") l
+
+let line_to_list line =
+ String.split_on_char ' ' line |> List.map (fun i -> int_of_string i)
+
+let is_valid_report l =
+ let rec increasing l =
+ match l with
+ | [] -> true
+ | [ _ ] -> true
+ | head :: h2 :: tail ->
+ if head >= h2 || h2 - head > 3 then false else increasing ([ h2 ] @ tail)
+ in
+ let rec decreasing l =
+ match l with
+ | [] -> true
+ | [ _ ] -> true
+ | head :: h2 :: tail ->
+ if head <= h2 || head - h2 > 3 then false else decreasing ([ h2 ] @ tail)
+ in
+
+ match l with
+ | [] -> true
+ | [ _ ] -> true
+ | h1 :: h2 :: tail ->
+ if h1 > h2 then decreasing ([ h1; h2 ] @ tail)
+ else increasing ([ h1; h2 ] @ tail)
+
+let rec range x y = if x > y then [] else x :: range (x + 1) y
+
+let list_premutations l =
+ let rec loop original_list nth index acc =
+ match original_list with
+ | [] -> acc
+ | head :: tail ->
+ if index == nth then loop tail nth (index + 1) acc
+ else loop tail nth (index + 1) ([ head ] @ acc)
+ in
+ let indexes = range 0 (List.length l - 1) in
+
+ let premutations =
+ List.fold_left
+ (fun acc index -> [ List.rev (loop l index 0 []) ] @ acc)
+ [] indexes
+ in
+ premutations
+
+let list_or l =
+ let rec loop l' acc =
+ match l' with [] -> acc | head :: tail -> head || loop tail acc
+ in
+ loop l false
+
+let solve lines =
+ let reports = List.map line_to_list lines in
+ let part1 =
+ List.fold_left
+ (fun acc i -> if is_valid_report i then acc + 1 else acc)
+ 0 reports
+ in
+ let premutations = List.map list_premutations reports in
+
+ let attempted_gaps =
+ List.map (fun i -> List.map is_valid_report i) premutations
+ in
+
+ let part2 =
+ List.fold_left
+ (fun acc bool_list -> if list_or bool_list then acc + 1 else acc)
+ 0 attempted_gaps
+ in
+ (part1, part2)