feat(aoc2024): day4 (#52)

aoc2024.ps1

@@ -6,8 +6,8 @@ param (
     [switch] $All,
     [switch] $NoBuild,
     [ValidateSet(
-        "day1", "day2", "day3"
-        # , "day4", "day5", "day6", "day7", "day8", "day9"
+        "day1", "day2", "day3", "day4"
+        # , "day5", "day6", "day7", "day8", "day9"
         # , "day10", "day11", "day12", "day13", "day14", "day15", "day16"
         # , "day17", "day18", "day19", "day20", "day21", "day22"
         # , "day23", "day24", "day25"

visp/examples/aoc2024/day4.visp

@@ -0,0 +1,133 @@
+
+;; Copyright 2024 Ville Penttinen
+;; Distributed under the MIT License.
+;; https://github.com/vipentti/visp-fs/blob/main/LICENSE.md
+;;
+;; for basic syntax highlighting
+;; vim: set syntax=clojure:
+
+;;
+;; day4
+;;
+;; Include common utlities
+(include "./common.visp")
+(include "./grid.visp")
+
+;; Functions & types
+
+(fn ParseFile ([text: string])
+  (mut lines (EnumerateSpanSplitLines text))
+
+  (let res (new ResizeArray<_>))
+
+  (Macro_ReadWhileNotEmpty [line lines]
+    ;; Read contents here
+    (.Add res (->> (.ToArray line)))
+    ())
+  (array2D (.ToArray res)))
+
+(fn Part1 (parsedInput)
+  ;; (printfn "%A" parsedInput)
+  (let H (Grid_Height parsedInput))
+  (let W (Grid_Width parsedInput))
+
+  (mut xmas_count 0)
+
+  (for/to [y (0 to (dec H))]
+    (for/to [x (0 to (dec W))]
+      (match (Grid_Get (x . y) parsedInput)
+        [(Some #\X)
+          ;; (printfn "X at %A" (x . y))
+
+          (for/in [offset POS_OFFSETS]
+            ;; todo
+            (let next (Pos_Add (x . y) offset))
+            (match (Grid_Get next parsedInput)
+              [(Some #\M)
+                ;; (printfn "M at %A" next)
+
+                (let next_next (Pos_Add next offset))
+
+                (match (Grid_Get next_next parsedInput)
+                  [(Some #\A)
+                    ;; (printfn "A at %A" next_next)
+
+                    (let next_next_next (Pos_Add next_next offset))
+
+                    (match (Grid_Get next_next_next parsedInput)
+                      [(Some #\S)
+                        ;; (printfn "S at %A" next_next_next)
+                        (up! xmas_count inc)
+                      ]
+                      [_ ()]
+                    )
+                  ]
+                  [_ ()]
+                )
+              ]
+              [_ ()]
+            ))
+        ]
+        [_ ()])
+      ))
+
+  ;; Implement part1
+  xmas_count)
+
+(fn IsChar [v ch]
+  (match v
+    [(Some x) (= x ch)]
+    [_ false]))
+
+(fn Part2 (parsedInput)
+  ;; Implement part2
+  (let H (Grid_Height parsedInput))
+  (let W (Grid_Width parsedInput))
+
+  (mut xmas_count 0)
+
+  (for/to [y (0 to (dec H))]
+    (for/to [x (0 to (dec W))]
+      (match (Grid_Get (x . y) parsedInput)
+        [(Some #\A)
+          (mut m_count 0)
+          (mut s_count 0)
+
+          (let up_left (Grid_Get (Pos_UpLeftOf (x . y)) parsedInput))
+          (let up_right (Grid_Get (Pos_UpRightOf (x . y)) parsedInput))
+          (let down_right (Grid_Get (Pos_DownRightOf (x . y)) parsedInput))
+          (let down_left (Grid_Get (Pos_DownLeftOf (x . y)) parsedInput))
+
+          (when_ (and (IsChar up_left #\M) (IsChar down_right #\S))
+            (up! m_count inc))
+
+          (when_ (and (IsChar up_left #\S) (IsChar down_right #\M))
+            (up! m_count inc))
+
+          (when_ (and (IsChar up_right #\M) (IsChar down_left #\S))
+            (up! s_count inc))
+
+          (when_ (and (IsChar up_right #\S) (IsChar down_left #\M))
+            (up! s_count inc))
+
+          (when_ (and (= m_count 1) (= s_count 1))
+            (up! xmas_count inc))
+          ()
+        ]
+        [_ ()]
+      )))
+
+  xmas_count)
+
+;; Implementation
+
+(let parsed (-> (ReadInput "day4") ParseFile))
+
+;; Expected results
+(let PART1_EXPECTED_RESULT (if IS_EXAMPLE 18 2370))
+(let PART2_EXPECTED_RESULT (if IS_EXAMPLE 9 1908))
+
+(WriteResult "part1" (-> parsed Part1) PART1_EXPECTED_RESULT)
+(WriteResult "part2" (-> parsed Part2) PART2_EXPECTED_RESULT)
+
+()

visp/examples/aoc2024/grid.visp

@@ -0,0 +1,33 @@
+;; Copyright 2024 Ville Penttinen
+;; Distributed under the MIT License.
+;; https://github.com/vipentti/visp-fs/blob/main/LICENSE.md
+;;
+;; for basic syntax highlighting
+;; vim: set syntax=clojure:
+
+(include "./pos.visp")
+
+(typedef Grid char[,])
+
+(fn inline Grid_Height ([g: Grid])
+  (Array2D.length1 g))
+
+(fn inline Grid_Width ([g: Grid])
+  (Array2D.length2 g))
+
+(fn inline Grid_RowSlice ([g: Grid] [col: int])
+  (.[*, col] g))
+
+(fn inline Grid_ColSlice ([g: Grid] [row: int])
+  (.[row, *] g))
+
+(fn inline Grid_Contains? ([(x, y): Pos] [g: Grid])
+  (and
+    (and (>= x 0) (< x (Grid_Width g)))
+    (and (>= y 0) (< y (Grid_Height g)))))
+
+(fn inline Grid_Get ([(x, y): Pos] [g: Grid])
+  (cond_
+    [(Grid_Contains? (x, y) g) (Some (.[y, x] g))]
+    [_ None]
+  ))

visp/examples/aoc2024/inputs/day4_example.txt

@@ -0,0 +1,10 @@
+MMMSXXMASM
+MSAMXMSMSA
+AMXSXMAAMM
+MSAMASMSMX
+XMASAMXAMM
+XXAMMXXAMA
+SMSMSASXSS
+SAXAMASAAA
+MAMMMXMMMM
+MXMXAXMASX

visp/examples/aoc2024/pos.visp

@@ -0,0 +1,43 @@
+;; Copyright 2024 Ville Penttinen
+;; Distributed under the MIT License.
+;; https://github.com/vipentti/visp-fs/blob/main/LICENSE.md
+;;
+;; for basic syntax highlighting
+;; vim: set syntax=clojure:
+
+(typedef Pos int * int)
+
+(fn inline Pos_Add ([(x, y): Pos] [(ox, oy): Pos]) ((+ x ox), (+ y oy)))
+(fn inline Pos_LeftOf ([(x, y): Pos]) ((dec x), y))
+(fn inline Pos_RightOf ([(x, y): Pos]) ((inc x), y))
+(fn inline Pos_UpOf ([(x, y): Pos]) (x, (dec y)))
+(fn inline Pos_DownOf ([(x, y): Pos]) (x, (inc y)))
+(fn inline Pos_UpLeftOf ([(x, y): Pos]) ((dec x), (dec y)))
+(fn inline Pos_UpRightOf ([(x, y): Pos]) ((inc x), (dec y)))
+(fn inline Pos_DownLeftOf ([(x, y): Pos]) ((dec x), (inc y)))
+(fn inline Pos_DownRightOf ([(x, y): Pos]) ((inc x), (inc y)))
+
+(let POS_CARDINALS [|
+  (0, -1)
+  (-1, 0)
+  (1, 0)
+  (0, 1)
+|])
+
+(let POS_OFFSETS [|
+  (-1, -1)
+  (0, -1)
+  (1, -1)
+  (-1, 0)
+  (1, 0)
+  (-1, 1)
+  (0, 1)
+  (1, 1)
+|])
+
+(let POS_DIAGONALS [|
+  (-1, -1)
+  (1, -1)
+  (-1, 1)
+  (1, 1)
+|])