AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/AdventOfCode2023.FSharp.Lib.fsproj

@@ -22,6 +22,7 @@
     <Compile Include="Day9.fs"/>
     <Compile Include="Day10.fs" />
     <Compile Include="Day11.fs" />
+    <Compile Include="Day12.fs" />
   </ItemGroup>
 
 </Project>

AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/Day11.fs

@@ -1,7 +1,5 @@
 namespace AdventOfCode2023
 
-open System
-
 [<RequireQualifiedAccess>]
 module Day11 =
 
@@ -41,7 +39,7 @@ module Day11 =
             let result = ResizeArray ()
             let mutable prevCol = 0
 
-            for (_, c) in galaxies do
+            for _, c in galaxies do
                 if c > prevCol then
                     for j = prevCol + 1 to c - 1 do
                         result.Add j

AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/Day12.fs

@@ -0,0 +1,196 @@
+namespace AdventOfCode2023
+
+open System
+open System.Collections.Generic
+open System.Globalization
+
+[<RequireQualifiedAccess>]
+module Day12 =
+
+    let rec solve
+        (dict : Dictionary<int * int, uint64>)
+        (line : ReadOnlySpan<char>)
+        (groups : IReadOnlyList<int>)
+        (remainingToFill : int)
+        (currentGroupIndex : int)
+        : uint64
+        =
+        if line.Length = 0 then
+            if currentGroupIndex = groups.Count then
+                LanguagePrimitives.GenericOne
+            else
+                LanguagePrimitives.GenericZero
+        elif currentGroupIndex = groups.Count then
+            if line.Contains '#' then
+                LanguagePrimitives.GenericZero
+            else
+                LanguagePrimitives.GenericOne
+        else
+
+        match dict.TryGetValue ((line.Length, currentGroupIndex)) with
+        | true, v -> v
+        | false, _ ->
+
+        if remainingToFill > line.Length then
+            dict.Add ((line.Length, currentGroupIndex), LanguagePrimitives.GenericZero)
+            LanguagePrimitives.GenericZero
+        else
+
+        match line.[0] with
+        | '#' ->
+            if currentGroupIndex >= groups.Count then
+                LanguagePrimitives.GenericZero
+            else
+                let mutable isOk = true
+
+                for i = 1 to groups.[currentGroupIndex] - 1 do
+                    if isOk && (i >= line.Length || (line.[i] <> '#' && line.[i] <> '?')) then
+                        isOk <- false
+
+                if not isOk then
+                    LanguagePrimitives.GenericZero
+                else if groups.[currentGroupIndex] < line.Length then
+                    if line.[groups.[currentGroupIndex]] = '#' then
+                        LanguagePrimitives.GenericZero
+                    else
+                        solve
+                            dict
+                            (line.Slice (groups.[currentGroupIndex] + 1))
+                            groups
+                            (remainingToFill - groups.[currentGroupIndex] - 1)
+                            (currentGroupIndex + 1)
+                else
+                    solve
+                        dict
+                        ReadOnlySpan<_>.Empty
+                        groups
+                        (remainingToFill - groups.[currentGroupIndex] - 1)
+                        (currentGroupIndex + 1)
+        | '.' -> solve dict (line.Slice 1) groups remainingToFill currentGroupIndex
+        | '?' ->
+            let afterMark = line.IndexOfAnyExcept ('?', '#')
+
+            if afterMark >= 0 && groups.[currentGroupIndex] > afterMark then
+                // this group would extend into a dot if this were filled in!
+                let firstHash = line.IndexOf '#'
+
+                if firstHash >= 0 && firstHash < afterMark then
+                    // this group *is* filled in, contradiction
+                    LanguagePrimitives.GenericZero
+                else
+                    solve dict (line.Slice afterMark) groups remainingToFill currentGroupIndex
+            else
+
+            let ifDot = solve dict (line.Slice 1) groups remainingToFill currentGroupIndex
+            dict.TryAdd ((line.Length - 1, currentGroupIndex), ifDot) |> ignore
+
+            let ifHash =
+                if currentGroupIndex >= groups.Count then
+                    LanguagePrimitives.GenericZero
+                else
+
+                let mutable isOk = true
+
+                for i = 1 to groups.[currentGroupIndex] - 1 do
+                    if isOk && (i >= line.Length || (line.[i] <> '#' && line.[i] <> '?')) then
+                        isOk <- false
+
+                if not isOk then
+                    LanguagePrimitives.GenericZero
+                else if groups.[currentGroupIndex] < line.Length then
+                    if
+                        groups.[currentGroupIndex] < line.Length
+                        && line.[groups.[currentGroupIndex]] = '#'
+                    then
+                        LanguagePrimitives.GenericZero
+                    else
+                        solve
+                            dict
+                            (line.Slice (groups.[currentGroupIndex] + 1))
+                            groups
+                            (remainingToFill - groups.[currentGroupIndex] - 1)
+                            (currentGroupIndex + 1)
+                else
+                    solve
+                        dict
+                        ReadOnlySpan<_>.Empty
+                        groups
+                        (remainingToFill - groups.[currentGroupIndex] - 1)
+                        (currentGroupIndex + 1)
+
+            let ans = ifDot + ifHash
+            dict.TryAdd ((line.Length, currentGroupIndex), ans) |> ignore
+            ans
+        | _ ->
+            if currentGroupIndex = groups.Count then
+                LanguagePrimitives.GenericOne
+            else
+                LanguagePrimitives.GenericZero
+
+    let part1 (s : string) =
+        use mutable lines = StringSplitEnumerator.make '\n' s
+
+        let mutable answer = 0uL
+        let arr = ResizeArray ()
+
+        let dict = Dictionary ()
+
+        for line in lines do
+            if not line.IsEmpty then
+                arr.Clear ()
+                use ints = StringSplitEnumerator.make' ',' (line.Slice (line.IndexOf ' ' + 1))
+
+                for int in ints do
+                    arr.Add (Int32.Parse (int, NumberStyles.None, CultureInfo.InvariantCulture))
+
+                let remainingToFill =
+                    let mutable ans = -1
+
+                    for i = 0 to arr.Count - 1 do
+                        ans <- ans + arr.[i] + 1
+
+                    ans
+
+                dict.Clear ()
+                let solved = solve dict line arr remainingToFill 0
+                answer <- answer + solved
+
+        answer
+
+    let part2 (s : string) =
+        use mutable lines = StringSplitEnumerator.make '\n' s
+
+        let mutable answer = 0uL
+        let arr = ResizeArray ()
+
+        let dict = Dictionary ()
+
+        for line in lines do
+            if not line.IsEmpty then
+                arr.Clear ()
+                let spaceIndex = line.IndexOf ' '
+
+                for _ = 0 to 4 do
+                    use ints = StringSplitEnumerator.make' ',' (line.Slice (spaceIndex + 1))
+
+                    for int in ints do
+                        arr.Add (Int32.Parse (int, NumberStyles.None, CultureInfo.InvariantCulture))
+
+                let sliced = line.Slice(0, spaceIndex).ToString ()
+
+                let line =
+                    String.Concat (sliced, '?', sliced, '?', sliced, '?', sliced, '?', sliced)
+
+                let remainingToFill =
+                    let mutable ans = -1
+
+                    for i = 0 to arr.Count - 1 do
+                        ans <- ans + arr.[i] + 1
+
+                    ans
+
+                dict.Clear ()
+                let solved = solve dict (line.AsSpan ()) arr remainingToFill 0
+                answer <- answer + solved
+
+        answer

AdventOfCode2023.FSharp/AdventOfCode2023.FSharp/Program.fs

@@ -217,12 +217,37 @@ module Program =
             let input = Path.Combine (dir.FullName, "day11.txt") |> File.ReadAllText
 
             sw.Restart ()
-            let part1 = Day11.part1 input
+            let data = Day11.parse input
+            sw.Stop ()
+
+            Console.Error.WriteLine (
+                (1_000.0 * float sw.ElapsedTicks / float Stopwatch.Frequency).ToString ()
+                + "ms parse"
+            )
+
+            sw.Restart ()
+            let part1 = Day11.solve data 2uL
             sw.Stop ()
             Console.WriteLine (part1.ToString ())
             Console.Error.WriteLine ((1_000.0 * float sw.ElapsedTicks / float Stopwatch.Frequency).ToString () + "ms")
             sw.Restart ()
-            let part2 = Day11.part2 input
+            let part2 = Day11.solve data 1_000_000uL
+            sw.Stop ()
+            Console.WriteLine (part2.ToString ())
+            Console.Error.WriteLine ((1_000.0 * float sw.ElapsedTicks / float Stopwatch.Frequency).ToString () + "ms")
+
+        Console.WriteLine "=====Day 12====="
+
+        do
+            let input = Path.Combine (dir.FullName, "day12.txt") |> File.ReadAllText
+
+            sw.Restart ()
+            let part1 = Day12.part1 input
+            sw.Stop ()
+            Console.WriteLine (part1.ToString ())
+            Console.Error.WriteLine ((1_000.0 * float sw.ElapsedTicks / float Stopwatch.Frequency).ToString () + "ms")
+            sw.Restart ()
+            let part2 = Day12.part2 input
             sw.Stop ()
             Console.WriteLine (part2.ToString ())
             Console.Error.WriteLine ((1_000.0 * float sw.ElapsedTicks / float Stopwatch.Frequency).ToString () + "ms")

AdventOfCode2023.FSharp/Test/Test.fsproj

@@ -20,6 +20,7 @@
     <Compile Include="TestDay9.fs"/>
     <Compile Include="TestDay10.fs" />
     <Compile Include="TestDay11.fs" />
+    <Compile Include="TestDay12.fs" />
     <EmbeddedResource Include="samples\day1.txt"/>
     <EmbeddedResource Include="samples\day1part1.txt"/>
     <EmbeddedResource Include="samples\day2.txt"/>
@@ -34,6 +35,7 @@
     <EmbeddedResource Include="samples\day10part1.txt" />
     <EmbeddedResource Include="samples\day10.txt" />
     <EmbeddedResource Include="samples\day11.txt" />
+    <EmbeddedResource Include="samples\day12.txt" />
   </ItemGroup>
 
   <ItemGroup>

AdventOfCode2023.FSharp/Test/TestDay12.fs

@@ -0,0 +1,45 @@
+namespace AdventOfCode2023.Test
+
+open AdventOfCode2023
+open NUnit.Framework
+open FsUnitTyped
+open System.IO
+
+[<TestFixture>]
+module TestDay12 =
+
+    let sample = Assembly.getEmbeddedResource typeof<Dummy>.Assembly "day12.txt"
+
+    [<Test>]
+    let part1Sample () =
+        sample |> Day12.part1 |> shouldEqual 21uL
+
+    [<Test>]
+    let part2Sample () =
+        sample |> Day12.part2 |> shouldEqual 525152uL
+
+    [<Test>]
+    let part1Actual () =
+        let s =
+            try
+                File.ReadAllText (Path.Combine (__SOURCE_DIRECTORY__, "../../inputs/day12.txt"))
+            with
+            | :? DirectoryNotFoundException
+            | :? FileNotFoundException ->
+                Assert.Inconclusive ()
+                failwith "unreachable"
+
+        Day12.part1 s |> shouldEqual 7402uL
+
+    [<Test>]
+    let part2Actual () =
+        let s =
+            try
+                File.ReadAllText (Path.Combine (__SOURCE_DIRECTORY__, "../../inputs/day12.txt"))
+            with
+            | :? DirectoryNotFoundException
+            | :? FileNotFoundException ->
+                Assert.Inconclusive ()
+                failwith "unreachable"
+
+        Day12.part2 s |> shouldEqual 3384337640277uL

AdventOfCode2023.FSharp/Test/samples/day12.txt

@@ -0,0 +1,6 @@
+???.### 1,1,3
+.??..??...?##. 1,1,3
+?#?#?#?#?#?#?#? 1,3,1,6
+????.#...#... 4,1,1
+????.######..#####. 1,6,5
+?###???????? 3,2,1