Day 1 part 2

.gitignore

@@ -1 +0,0 @@
-inputs

ocaml/1.ml

@@ -1,12 +1,19 @@
 #load "str.cma" ;;
 #use "lib/file_utils.ml" ;;
 
+let top n calories =
+  let topn = List.filteri (fun i _ -> i < n) calories in
+  let numcal = List.fold_left (+) 0 topn in
+  Printf.printf "Top %d: %d\n" n numcal
+;;
+
+let order_desc a b = if a < b then 1 else -1 in
 let contents = read_file "inputs/1.txt" in
-let maxcal = Str.split (Str.regexp "\n\n") contents
+let calories = Str.split (Str.regexp "\n\n") contents
   |> List.map (String.split_on_char '\n')
   |> List.map (List.map (int_of_string))
   |> List.map (List.fold_left (+) 0)
-  |> List.fold_left (max) 0
-  in
-
-Printf.printf "%d" maxcal
+  |> List.sort order_desc
+in
+top 1 calories;
+top 3 calories

ocaml/2.ml

@@ -0,0 +1,73 @@
+#use "lib/file_utils.ml" ;;
+
+type shape = Rock | Paper | Scissors
+type outcome = Win | Tie | Loss
+
+let shape_of_char = function
+  | 'A' | 'X' -> Rock
+  | 'B' | 'Y' -> Paper
+  | 'C' | 'Z' -> Scissors
+  | s -> failwith ("invalid shape: " ^ (String.make 1 s))
+
+let score_of_shape = function
+  | Rock -> 1
+  | Paper -> 2
+  | Scissors -> 3
+
+let score_of_outcome = function
+  | Loss -> 0
+  | Tie -> 3
+  | Win -> 6
+
+let part1 line =
+  let outcome_of_round = function
+    | Rock, Scissors -> Win
+    | Paper, Rock -> Win
+    | Scissors, Paper -> Win
+    | a, b when a = b -> Tie
+    | _ -> Loss
+  in
+  let op_move = shape_of_char (String.get line 0) in
+  let my_move = shape_of_char (String.get line 2) in
+  let outcome = outcome_of_round(my_move, op_move) in
+  let outcome_score = score_of_outcome outcome in
+  let shape_score = score_of_shape my_move in
+  outcome_score + shape_score
+
+let part2 line =
+  let outcome_of_char = function
+    | 'X' -> Loss
+    | 'Y' -> Tie
+    | 'Z' -> Win
+    | o -> failwith ("invalid outcome: " ^ (String.make 1 o))
+  in
+  let make_move = function
+    | Rock, Win -> Paper
+    | Rock, Loss -> Scissors
+    | Paper, Win -> Scissors
+    | Paper, Loss -> Rock
+    | Scissors, Win -> Rock
+    | Scissors, Loss -> Paper
+    | s, Tie -> s
+  in
+  let op_move = shape_of_char (String.get line 0) in
+  let outcome = outcome_of_char (String.get line 2) in
+  let my_move = make_move(op_move, outcome) in
+  let outcome_score = score_of_outcome outcome in
+  let shape_score = score_of_shape my_move in
+  outcome_score + shape_score
+
+let play lines part rules =
+  let score = lines
+    |> List.map rules
+    |> List.fold_left (+) 0
+  in
+  Printf.printf "Part %d: %d\n" part score
+;;
+
+let contents = read_file "inputs/2.txt" in
+let lines = String.split_on_char '\n' contents
+  |> List.filter (fun l -> String.trim l <> "")
+in
+play lines 1 part1;
+play lines 2 part2