Publish

.woodpecker/.build.yml

@@ -11,8 +11,9 @@ steps:
       - nix develop --command alejandra --check .
       - nix develop --command dotnet tool restore
       - nix develop --command dotnet fantomas --check .
-      # - nix develop --command dotnet publish AdventOfCode2023.FSharp/AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.fsproj --configuration Release
+      # TODO: if https://github.com/dotnet/sdk/issues/37295 ever gets fixed, remove the PublishAot=false
-      # - nix develop --command sh -c "$(find . -type f -name AdventOfCode2023.FSharp | grep Release | grep publish) AdventOfCode2023.FSharp/Test/samples"
+      - "nix develop --command dotnet publish AdventOfCode2023.FSharp/AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.fsproj --configuration Release -p:PublishAot=false"
+      - nix develop --command sh -c "$(find . -type f -name AdventOfCode2023.FSharp | grep Release | grep publish) AdventOfCode2023.FSharp/Test/samples"
 
     when:
       - event: "push"

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

@@ -14,6 +14,7 @@
         <Compile Include="Day4.fs" />
         <Compile Include="Day5.fs" />
         <Compile Include="Day6.fs" />
+        <Compile Include="Day7.fs" />
     </ItemGroup>
 
 </Project>

AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/Day1.fs

@@ -5,21 +5,13 @@ open System
 [<RequireQualifiedAccess>]
 module Day1 =
 
-    let firstDigit (s : ReadOnlySpan<char>) =
+    let inline firstDigit (s : ReadOnlySpan<char>) =
-        let mutable pos = 0
+        let pos = s.IndexOfAnyInRange ('0', '9')
-
-        while '0' > s.[pos] || s.[pos] > '9' do
-            pos <- pos + 1
-
         byte s.[pos] - byte '0'
 
     // No surrogate pairs please!
-    let lastDigit (s : ReadOnlySpan<char>) =
+    let inline lastDigit (s : ReadOnlySpan<char>) =
-        let mutable pos = s.Length - 1
+        let pos = s.LastIndexOfAnyInRange ('0', '9')
-
-        while '0' > s.[pos] || s.[pos] > '9' do
-            pos <- pos - 1
-
         byte s.[pos] - byte '0'
 
     let part1 (s : string) =
@@ -35,35 +27,66 @@ module Day1 =
 
         total
 
-    let table =
+    let isDigitSpelled (s : ReadOnlySpan<char>) (pos : int) (answer : byref<byte>) =
-        [|
+        // Can't be bothered to write a jump-table compiler
-            "one", 1uy
+        if s.[pos] >= '0' && s.[pos] <= '9' then
-            "two", 2uy
+            answer <- byte s.[pos] - byte '0'
-            "three", 3uy
+        else if s.[pos] = 'o' then
-            "four", 4uy
+            if pos + 2 < s.Length && s.[pos + 1] = 'n' && s.[pos + 2] = 'e' then
-            "five", 5uy
+                answer <- 1uy
-            "six", 6uy
+        elif s.[pos] = 't' then
-            "seven", 7uy
+            if pos + 2 < s.Length && s.[pos + 1] = 'w' && s.[pos + 2] = 'o' then
-            "eight", 8uy
+                answer <- 2uy
-            "nine", 9uy
+            elif
-        |]
+                pos + 4 < s.Length
+                && s.[pos + 1] = 'h'
+                && s.[pos + 2] = 'r'
+                && s.[pos + 3] = 'e'
+                && s.[pos + 4] = 'e'
+            then
+                answer <- 3uy
+        elif s.[pos] = 'f' then
+            if pos + 3 < s.Length then
+                if s.[pos + 1] = 'o' && s.[pos + 2] = 'u' && s.[pos + 3] = 'r' then
+                    answer <- 4uy
+                elif s.[pos + 1] = 'i' && s.[pos + 2] = 'v' && s.[pos + 3] = 'e' then
+                    answer <- 5uy
+        elif s.[pos] = 's' then
+            if pos + 2 < s.Length && s.[pos + 1] = 'i' && s.[pos + 2] = 'x' then
+                answer <- 6uy
+            elif
+                pos + 4 < s.Length
+                && s.[pos + 1] = 'e'
+                && s.[pos + 2] = 'v'
+                && s.[pos + 3] = 'e'
+                && s.[pos + 4] = 'n'
+            then
+                answer <- 7uy
+        elif s.[pos] = 'e' then
+            if
+                pos + 4 < s.Length
+                && s.[pos + 1] = 'i'
+                && s.[pos + 2] = 'g'
+                && s.[pos + 3] = 'h'
+                && s.[pos + 4] = 't'
+            then
+                answer <- 8uy
+        elif s.[pos] = 'n' then
+            if
+                pos + 3 < s.Length
+                && s.[pos + 1] = 'i'
+                && s.[pos + 2] = 'n'
+                && s.[pos + 3] = 'e'
+            then
+                answer <- 9uy
 
     let firstDigitIncSpelled (s : ReadOnlySpan<char>) =
         let mutable pos = 0
         let mutable answer = 255uy
 
         while answer = 255uy do
-            if s.[pos] >= '0' && s.[pos] <= '9' then
+            isDigitSpelled s pos &answer
-                answer <- byte s.[pos] - byte '0'
+            pos <- pos + 1
-            else
-                for i, value in table do
-                    if
-                        pos + i.Length < s.Length
-                        && MemoryExtensions.SequenceEqual (s.Slice (pos, i.Length), i)
-                    then
-                        answer <- value
-
-                pos <- pos + 1
 
         answer
 
@@ -72,17 +95,8 @@ module Day1 =
         let mutable answer = 255uy
 
         while answer = 255uy do
-            if s.[pos] >= '0' && s.[pos] <= '9' then
+            isDigitSpelled s pos &answer
-                answer <- byte s.[pos] - byte '0'
+            pos <- pos - 1
-            else
-                for i, value in table do
-                    if
-                        pos - i.Length + 1 >= 0
-                        && MemoryExtensions.SequenceEqual (s.Slice (pos - i.Length + 1, i.Length), i)
-                    then
-                        answer <- value
-
-                pos <- pos - 1
 
         answer
 

AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/Day3.fs

@@ -146,7 +146,7 @@ module Day3 =
 
         let mutable answer = 0
 
-        for KeyValue (_gearPos, gears) in gears do
+        for gears in gears.Values do
             if gears.Count = 2 then
                 answer <- answer + gears.[0] * gears.[1]
 

AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/Day4.fs

@@ -54,8 +54,6 @@ module Day4 =
 
         total
 
-
-
     let part2 (s : string) =
         use lines = StringSplitEnumerator.make '\n' s
         let winningNumbers = ResizeArray<byte> ()

AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/Day7.fs

@@ -0,0 +1,86 @@
+namespace AdventOfCode2023
+
+open System
+
+[<RequireQualifiedAccess>]
+module Day7 =
+
+    let parse (s : string) =
+        use mutable lines = StringSplitEnumerator.make '\n' s
+
+        let times =
+            lines.MoveNext () |> ignore
+            use mutable line = StringSplitEnumerator.make' ' ' lines.Current
+            StringSplitEnumerator.chomp "Time:" &line
+            line.MoveNext () |> ignore
+            let times = ResizeArray ()
+
+            while line.MoveNext () do
+                if not line.Current.IsEmpty then
+                    times.Add (UInt64.Parse line.Current)
+
+            times
+
+        let distance =
+            lines.MoveNext () |> ignore
+            use mutable line = StringSplitEnumerator.make' ' ' lines.Current
+            StringSplitEnumerator.chomp "Distance:" &line
+            line.MoveNext () |> ignore
+            let distance = ResizeArray ()
+
+            while line.MoveNext () do
+                if not line.Current.IsEmpty then
+                    distance.Add (UInt64.Parse line.Current)
+
+            distance
+
+        times, distance
+
+    let furthest (distance : uint64) (toBeat : uint64) =
+        // Count i in [1 .. distance - 1] such that (distance - i) * i > toBeat
+        // i.e. such that distance * i - i * i > toBeat
+        // -i^2 + distance * i - toBeat = 0 when:
+        // i = (distance +- sqrt(distance^2 - 4 * toBeat)) / 2
+        let distFloat = float distance
+        let inside = sqrt (distFloat * distFloat - 4.0 * float toBeat)
+        let limit1 = (distFloat + inside) / 2.0
+        let limit2 = (distFloat - sqrt (distFloat * distFloat - 4.0 * float toBeat)) / 2.0
+        // round limit2 up and limit1 down
+        let limit1 = uint64 (floor limit1)
+        let limit2 = uint64 (ceil limit2)
+        // cope with edge case of an exact square
+        if (uint64 inside) * (uint64 inside) = uint64 distance * uint64 distance - 4uL * uint64 toBeat then
+            limit1 - limit2 - 1uL
+        else
+            limit1 - limit2 + 1uL
+
+    let part1 (s : string) =
+        let times, distance = parse s
+        let mutable answer = 1uL
+
+        for i = 0 to times.Count - 1 do
+            let time = times.[i]
+            let distance = distance.[i]
+            let winners = furthest time distance
+            answer <- answer * winners
+
+        answer
+
+    let concat (digits : ResizeArray<uint64>) : uint64 =
+        let mutable answer = 0uL
+
+        for digit in digits do
+            let mutable power = 10uL
+
+            while digit >= power do
+                power <- power * 10uL
+
+            answer <- answer * power + digit
+
+        answer
+
+    let part2 (s : string) =
+        let times, distance = parse s
+        let concatTime = concat times
+        let concatDist = concat distance
+        furthest concatTime concatDist

AdventOfCode2023.FSharp/AdventOfCode2023.FSharp/Program.fs

@@ -136,6 +136,21 @@ module Program =
             Console.WriteLine (part2.ToString ())
             Console.Error.WriteLine ((1_000.0 * float sw.ElapsedTicks / float Stopwatch.Frequency).ToString () + "ms")
 
+        printfn "=====Day 7====="
+
+        do
+            let input = Path.Combine (dir.FullName, "day7.txt") |> File.ReadAllText
+            sw.Restart ()
+            let part1 = Day7.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 = Day7.part2 input
+            sw.Stop ()
+            Console.WriteLine (part2.ToString ())
+            Console.Error.WriteLine ((1_000.0 * float sw.ElapsedTicks / float Stopwatch.Frequency).ToString () + "ms")
+
         endToEnd.Stop ()
 
         Console.Error.WriteLine (

AdventOfCode2023.FSharp/Test/Test.fsproj

@@ -15,6 +15,7 @@
         <Compile Include="TestDay4.fs" />
         <Compile Include="TestDay5.fs" />
         <Compile Include="TestDay6.fs" />
+        <Compile Include="TestDay7.fs" />
         <EmbeddedResource Include="samples\day1.txt" />
         <EmbeddedResource Include="samples\day1part1.txt" />
         <EmbeddedResource Include="samples\day2.txt" />
@@ -22,6 +23,7 @@
         <EmbeddedResource Include="samples\day4.txt" />
         <EmbeddedResource Include="samples\day5.txt" />
         <EmbeddedResource Include="samples\day6.txt" />
+        <EmbeddedResource Include="samples\day7.txt" />
     </ItemGroup>
 
     <ItemGroup>

AdventOfCode2023.FSharp/Test/TestDay7.fs

@@ -0,0 +1,46 @@
+namespace AdventOfCode2023.Test
+
+open System
+open AdventOfCode2023
+open NUnit.Framework
+open FsUnitTyped
+open System.IO
+
+[<TestFixture>]
+module TestDay7 =
+
+    let sample = Assembly.getEmbeddedResource typeof<Dummy>.Assembly "day7.txt"
+
+    [<Test>]
+    let part1Sample () =
+        sample |> Day7.part1 |> shouldEqual 288uL
+
+    [<Test>]
+    let part2Sample () =
+        sample |> Day7.part2 |> shouldEqual 71503uL
+
+    [<Test>]
+    let part1Actual () =
+        let s =
+            try
+                File.ReadAllText (Path.Combine (__SOURCE_DIRECTORY__, "../../inputs/day6.txt"))
+            with
+            | :? DirectoryNotFoundException
+            | :? FileNotFoundException ->
+                Assert.Inconclusive ()
+                failwith "unreachable"
+
+        Day7.part1 s |> shouldEqual 32076uL
+
+    [<Test>]
+    let part2Actual () =
+        let s =
+            try
+                File.ReadAllText (Path.Combine (__SOURCE_DIRECTORY__, "../../inputs/day6.txt"))
+            with
+            | :? DirectoryNotFoundException
+            | :? FileNotFoundException ->
+                Assert.Inconclusive ()
+                failwith "unreachable"
+
+        Day7.part2 s |> shouldEqual 34278221uL