Perhaps a bit more efficient (#12)

AdventOfCode2022/AdventOfCode2022.fsproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-      <TargetFramework>net6.0</TargetFramework>
+      <TargetFramework>net7.0</TargetFramework>
       <GenerateDocumentationFile>true</GenerateDocumentationFile>
       <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     </PropertyGroup>

AdventOfCode2022/Day5.fs

@@ -1,6 +1,7 @@
 namespace AdventOfCode2022
 
 open System
+open System.Collections.Generic
 
 type Day5Instruction =
     {
@@ -17,7 +18,7 @@ module Day5 =
         while enumerator.MoveNext () && not (enumerator.Current.IsWhiteSpace ()) do
             let s = enumerator.Current
 
-            if s.Contains ']' then
+            if s.IndexOf ']' >= 0 then
                 for i in 1..4 .. s.Length - 1 do
                     let pile = (i - 1) / 4
 
@@ -30,7 +31,7 @@ module Day5 =
 
         Array.init piles.Count (fun i -> List.init piles.[i].Count (fun j -> piles.[i].[j]))
 
-    let rec private parseInstruction (enumerator : byref<StringSplitEnumerator>) =
+    let rec private parseInstruction (enumerator : byref<StringSplitEnumerator>) : Day5Instruction IReadOnlyList =
         let outputs = ResizeArray ()
 
         while (enumerator.MoveNext ()) && (not (enumerator.Current.IsWhiteSpace ())) do
@@ -59,9 +60,9 @@ module Day5 =
             }
             |> outputs.Add
 
-        List.init outputs.Count (fun i -> outputs.[i])
+        outputs
 
-    let parse (s : StringSplitEnumerator) : char list array * Day5Instruction list =
+    let parse (s : StringSplitEnumerator) : char list array * Day5Instruction IReadOnlyList =
         use mutable enumerator = s
 
         let piles = parseDrawing &enumerator
@@ -71,26 +72,23 @@ module Day5 =
     let part1 (lines : StringSplitEnumerator) : string =
         let piles, instructions = parse lines
 
-        let rec go (instructions : _ list) (piles : _ list array) =
-            match instructions with
-            | [] -> piles
-            | instr :: rest ->
+        let go (instructions : _ IReadOnlyList) (piles : _ list array) =
+            for instr in instructions do
                 piles.[instr.To - 1] <- List.rev piles.[instr.From - 1].[0 .. instr.Count - 1] @ piles.[instr.To - 1]
                 piles.[instr.From - 1] <- piles.[instr.From - 1].[instr.Count ..]
 
-                go rest piles
+            piles
 
         String (go instructions piles |> Array.map List.head)
 
     let part2 (lines : StringSplitEnumerator) : string =
         let piles, instructions = parse lines
 
-        let rec go (instructions : _ list) (piles : _ list array) =
-            match instructions with
-            | [] -> piles
-            | instr :: rest ->
+        let rec go (instructions : _ IReadOnlyList) (piles : _ list array) =
+            for instr in instructions do
                 piles.[instr.To - 1] <- piles.[instr.From - 1].[0 .. instr.Count - 1] @ piles.[instr.To - 1]
                 piles.[instr.From - 1] <- piles.[instr.From - 1].[instr.Count ..]
-                go rest piles
+
+            piles
 
         String (go instructions piles |> Array.map List.head)

AdventOfCode2022/Day7.fs

@@ -177,5 +177,5 @@ module Day7 =
         let required = 30000000 - unused
 
         results
-        |> Seq.choose (fun (KeyValue (path, size)) -> if size >= required then Some size else None)
+        |> Seq.choose (fun (KeyValue (_, size)) -> if size >= required then Some size else None)
         |> Seq.min

AdventOfCode2022/Day8.fs

@@ -26,12 +26,12 @@ module Day8 =
         output :> _
 
     let isVisible (board : byte[] IReadOnlyList) (x : int) (y : int) : bool =
-        // From the top?
+        // From the left?
         let mutable isVisible = true
         let mutable i = 0
 
-        while i < y && isVisible do
-            if board.[i].[x] >= board.[y].[x] then
+        while i < x && isVisible do
+            if board.[y].[i] >= board.[y].[x] then
                 isVisible <- false
 
             i <- i + 1
@@ -40,12 +40,12 @@ module Day8 =
             true
         else
 
-        // From the bottom?
+        // From the right?
         let mutable isVisible = true
-        let mutable i = board.Count - 1
+        let mutable i = board.[0].Length - 1
 
-        while i > y && isVisible do
-            if board.[i].[x] >= board.[y].[x] then
+        while i > x && isVisible do
+            if board.[y].[i] >= board.[y].[x] then
                 isVisible <- false
 
             i <- i - 1
@@ -54,12 +54,12 @@ module Day8 =
             true
         else
 
-            // From the left?
+            // From the top?
             let mutable isVisible = true
             let mutable i = 0
 
-            while i < x && isVisible do
-                if board.[y].[i] >= board.[y].[x] then
+            while i < y && isVisible do
+                if board.[i].[x] >= board.[y].[x] then
                     isVisible <- false
 
                 i <- i + 1
@@ -68,17 +68,17 @@ module Day8 =
                 true
             else
 
-                // From the right?
-                let mutable isVisible = true
-                let mutable i = board.[0].Length - 1
+            // From the bottom?
+            let mutable isVisible = true
+            let mutable i = board.Count - 1
 
-                while i > x && isVisible do
-                    if board.[y].[i] >= board.[y].[x] then
-                        isVisible <- false
+            while i > y && isVisible do
+                if board.[i].[x] >= board.[y].[x] then
+                    isVisible <- false
 
-                    i <- i - 1
+                i <- i - 1
 
-                isVisible
+            isVisible
 
     let part1 (lines : StringSplitEnumerator) : int =
         let board = parse lines