Feature/aoc2024/day2

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/common.visp

@@ -24,6 +24,9 @@
 (fn EnumareteSpanSplitChars ([ch: array<char>] [text: ReadOnlySpan<char>])
   (.EnumerateSplitSubstrings text ch commonSplitOptions))
 
+(fn EnumerateSpaceSeparated ([text: ReadOnlySpan<char>])
+  (.EnumerateSplitSubstrings text [| #\space |] (bor StringSplitOptions.TrimEntries StringSplitOptions.RemoveEmptyEntries)))
+
 (fn ReadInput ([day: string])
   (let filepath (String.concat "" [| "./inputs/" day (if IS_EXAMPLE "_example" "") ".txt" |]))
   (printfn "file: %s" filepath)

visp/examples/aoc2024/day2.visp

@@ -0,0 +1,107 @@
+
+;; 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:
+
+;;
+;; day2
+;;
+;; Include common utlities
+(include "./common.visp")
+
+;; Functions & types
+
+(fn ParseFile ([text: string])
+  (mut lines (EnumerateSpanSplitLines text))
+
+  (mut data (||))
+
+  (Macro_ReadWhileNotEmpty [line lines]
+    ;; Read contents here
+    (mut parts (EnumerateSpaceSeparated line))
+
+    (mut items (||))
+
+    (Macro_ReadWhileNotEmpty [part parts]
+      (up! items (cons (span->int32 part))))
+
+    (up! data (cons (List.rev items)))
+
+    ())
+
+  (List.rev data))
+
+(fn IsSafeList (lst)
+  (-> lst
+    (List.pairwise)
+    (List.fold
+      #(begin
+        (let [(valid, validDiff) : bool * int32] %1)
+
+        (if (not valid)
+          (false . 0)
+          (begin
+            (let [(lhs, rhs) : int32 * int32] %2)
+            (let diff (- rhs lhs))
+            (let diff_sign (int32->sign diff))
+            (let abs_diff (abs diff))
+            (let safe (and (>= abs_diff 1) (<= abs_diff 3)))
+
+            (cond_
+              [(and safe (= validDiff 0))
+                (true . diff_sign)]
+
+              [(and safe (= validDiff diff_sign))
+                (true . diff_sign)
+              ]
+              [_ (false . 0)])
+          ))) (true . 0))
+    fst))
+
+(fn OneRemoved (lst)
+  (mut lists (||))
+
+  (for/in [idx (!r 0 .. 1 .. (dec (List.length lst)))]
+    (up! lists (cons (List.removeAt idx lst))))
+
+  lists)
+
+(fn Part1 (parsedInput)
+  ;; (printfn "%A" parsedInput)
+
+  ;; Implement part1
+  (-> parsedInput
+    (List.filter IsSafeList)
+    (List.length)
+  ))
+
+(fn Part2 (parsedInput)
+  ;; Implement part2
+  (-> parsedInput
+    (List.filter #(begin
+      (let origSafe (IsSafeList %1))
+      (if origSafe
+        true
+        (begin
+          (-> (OneRemoved %1)
+              (List.exists IsSafeList))
+        ))
+    ))
+    (List.length)
+  ))
+
+;; Implementation
+
+(let parsed (-> (ReadInput "day2") ParseFile))
+
+;; Expected results
+(let PART1_EXPECTED_RESULT (if IS_EXAMPLE 2 606))
+(let PART2_EXPECTED_RESULT (if IS_EXAMPLE 4 644))
+
+(WriteResult "part1" (-> parsed Part1) PART1_EXPECTED_RESULT)
+(WriteResult "part2" (-> parsed Part2) PART2_EXPECTED_RESULT)
+
+()

visp/examples/aoc2024/inputs/day2_example.txt

@@ -0,0 +1,6 @@
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9

visp/lib/core.visp

@@ -101,6 +101,9 @@
     [(x, y) (gcd64 y (rem x y))]
   ))
 
+(fn inline int32->sign [(a: int32)] (System.Math.Sign a))
+(fn inline int64->sign [(a: int64)] (System.Math.Sign a))
+
 (fn inline lcm64 (a b)
   (/ (* a b) (gcd64 a b)))