Day 2 part 1

ocaml/2.ml

@@ -0,0 +1,49 @@
+#use "lib/file_utils.ml" ;;
+
+type shape = Rock | Paper | Scissors
+type outcome = Win | Tie | Loss
+
+let shape_of = 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 outcome_of = function
+  | Rock, Scissors -> Win
+  | Paper, Rock -> Win
+  | Scissors, Paper -> Win
+  | a, b when a = b -> Tie
+  | _ -> Loss
+;;
+
+let play_round line =
+  let op_move = shape_of (String.get line 0) in
+  let my_move = shape_of (String.get line 2) in
+  let outcome = outcome_of(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 contents = read_file "inputs/2.txt" in
+let score = String.split_on_char '\n' contents
+  |> List.filter (fun l -> String.trim l <> "")
+  |> List.map play_round
+  |> List.fold_left (+) 0
+in
+
+Printf.printf "%d" score