diff --git a/src/day8.ml b/src/day8.ml
index c4f80b2..fabe7ea 100644
--- a/src/day8.ml
+++ b/src/day8.ml
@@ -18,7 +18,7 @@ end = struct
 
   let at grid point =
     let x, y = to_tuple point in
-    let open Option in
+    let open Option.Infix in
     let* row = Array.get_safe grid y in
     Array.get_safe row x
   ;;
@@ -32,60 +32,54 @@ let parse_grid () =
        Fun.(String.to_seq %> Seq.map (Char.to_string %> int_of_string) %> Seq.to_array)
 ;;
 
-let rec find_taller_tree grid start_height start step =
-  let next = Vec2.(start + step) in
-  match Vec2.at grid next with
-  | Some height when height < start_height -> find_taller_tree grid start_height next step
-  | opt -> opt
+let solve grid fn =
+  let grid_h = Array.length grid in
+  let grid_w = Array.length grid.(0) in
+  for y = 0 to grid_h - 1 do
+    for x = 0 to grid_w - 1 do
+      let start = Vec2.of_tuple (x, y) in
+      fn start
+    done
+  done
 ;;
 
 let part1 () =
   let grid = parse_grid () in
-  let grid_h = Array.length grid in
-  let grid_w = Array.length grid.(0) in
   let num_visible = ref 0 in
-  for y = 0 to grid_h - 1 do
-    for x = 0 to grid_w - 1 do
-      let start = Vec2.of_tuple (x, y) in
-      let height = Option.get_exn_or "unreachable" @@ Vec2.at grid start in
-      let visible =
-        Vec2.directions
-        |> List.map @@ find_taller_tree grid height start
-        |> List.map Option.is_none
-        |> List.reduce_exn ( || )
-      in
-      if visible then incr num_visible
-    done
-  done;
+  solve grid (fun start ->
+    let start_height = Option.get_exn_or "unreachable" @@ Vec2.at grid start in
+    let rec walk_shorter_trees start step =
+      let next = Vec2.(start + step) in
+      match Vec2.at grid next with
+      | Some height when height < start_height -> walk_shorter_trees next step
+      | opt -> opt
+    in
+    let visible =
+      Vec2.directions
+      |> List.map @@ walk_shorter_trees start
+      |> List.map Option.is_none
+      |> List.reduce_exn ( || )
+    in
+    if visible then incr num_visible);
   !num_visible
 ;;
 
-let rec trees_in_view grid start start_height in_view step =
-  let next = Vec2.(start + step) in
-  match Vec2.at grid next with
-  | Some height when height < start_height ->
-    trees_in_view grid next start_height (in_view + 1) step
-  | Some _ -> in_view + 1
-  | None -> in_view
-;;
-
 let part2 () =
   let grid = parse_grid () in
-  let grid_h = Array.length grid in
-  let grid_w = Array.length grid.(0) in
   let best_score = ref 0 in
-  for y = 0 to grid_h - 1 do
-    for x = 0 to grid_w - 1 do
-      let start = Vec2.of_tuple (x, y) in
-      let height = Option.get_exn_or "unreachable" @@ Vec2.at grid start in
-      let score =
-        Vec2.directions
-        |> List.map @@ trees_in_view grid start height 0
-        |> List.reduce_exn ( * )
-      in
-      if score > !best_score then best_score := score
-    done
-  done;
+  solve grid (fun start ->
+    let start_height = Option.get_exn_or "unreachable" @@ Vec2.at grid start in
+    let rec trees_in_view start in_view step =
+      let next = Vec2.(start + step) in
+      match Vec2.at grid next with
+      | Some height when height < start_height -> trees_in_view next (in_view + 1) step
+      | Some _ -> in_view + 1
+      | None -> in_view
+    in
+    let score =
+      Vec2.directions |> List.map @@ trees_in_view start 0 |> List.reduce_exn ( * )
+    in
+    if score > !best_score then best_score := score);
   !best_score
 ;;