apply editorconfig

.editorconfig

@@ -0,0 +1,270 @@
+# Remove the line below if you want to inherit .editorconfig settings from higher directories
+root = true
+
+# C# files
+[*.cs]
+
+#### Core EditorConfig Options ####
+
+# Indentation and spacing
+indent_size = 4
+indent_style = tab
+tab_width = 4
+
+# New line preferences
+end_of_line = crlf
+insert_final_newline = false
+
+#### .NET Coding Conventions ####
+
+# Organize usings
+dotnet_separate_import_directive_groups = false
+dotnet_sort_system_directives_first = false
+file_header_template = unset
+
+# this. and Me. preferences
+dotnet_style_qualification_for_event = false
+dotnet_style_qualification_for_field = false
+dotnet_style_qualification_for_method = false
+dotnet_style_qualification_for_property = false
+
+# Language keywords vs BCL types preferences
+dotnet_style_predefined_type_for_locals_parameters_members = true
+dotnet_style_predefined_type_for_member_access = true
+
+# Parentheses preferences
+dotnet_style_parentheses_in_arithmetic_binary_operators = always_for_clarity
+dotnet_style_parentheses_in_other_binary_operators = always_for_clarity
+dotnet_style_parentheses_in_other_operators = never_if_unnecessary
+dotnet_style_parentheses_in_relational_binary_operators = always_for_clarity
+
+# Modifier preferences
+dotnet_style_require_accessibility_modifiers = for_non_interface_members
+
+# Expression-level preferences
+dotnet_style_coalesce_expression = true
+dotnet_style_collection_initializer = true
+dotnet_style_explicit_tuple_names = true
+dotnet_style_namespace_match_folder = true
+dotnet_style_null_propagation = true
+dotnet_style_object_initializer = true
+dotnet_style_operator_placement_when_wrapping = beginning_of_line
+dotnet_style_prefer_auto_properties = true
+dotnet_style_prefer_collection_expression = true
+dotnet_style_prefer_compound_assignment = true
+dotnet_style_prefer_conditional_expression_over_assignment = true
+dotnet_style_prefer_conditional_expression_over_return = true
+dotnet_style_prefer_foreach_explicit_cast_in_source = when_strongly_typed
+dotnet_style_prefer_inferred_anonymous_type_member_names = true
+dotnet_style_prefer_inferred_tuple_names = true
+dotnet_style_prefer_is_null_check_over_reference_equality_method = true
+dotnet_style_prefer_simplified_boolean_expressions = true
+dotnet_style_prefer_simplified_interpolation = true
+
+# Field preferences
+dotnet_style_readonly_field = true
+
+# Parameter preferences
+dotnet_code_quality_unused_parameters = all
+
+# Suppression preferences
+dotnet_remove_unnecessary_suppression_exclusions = none
+
+# New line preferences
+dotnet_style_allow_multiple_blank_lines_experimental = false
+dotnet_style_allow_statement_immediately_after_block_experimental = false
+
+#### C# Coding Conventions ####
+
+# var preferences
+csharp_style_var_elsewhere = true:silent
+csharp_style_var_for_built_in_types = true:silent
+csharp_style_var_when_type_is_apparent = true:silent
+
+# Expression-bodied members
+csharp_style_expression_bodied_accessors = true:silent
+csharp_style_expression_bodied_constructors = true:silent
+csharp_style_expression_bodied_indexers = true:silent
+csharp_style_expression_bodied_lambdas = true:silent
+csharp_style_expression_bodied_local_functions = true:silent
+csharp_style_expression_bodied_methods = true:silent
+csharp_style_expression_bodied_operators = true:silent
+csharp_style_expression_bodied_properties = true:silent
+
+# Pattern matching preferences
+csharp_style_pattern_matching_over_as_with_null_check = true:suggestion
+csharp_style_pattern_matching_over_is_with_cast_check = true:suggestion
+csharp_style_prefer_extended_property_pattern = true:suggestion
+csharp_style_prefer_not_pattern = true:suggestion
+csharp_style_prefer_pattern_matching = true:silent
+csharp_style_prefer_switch_expression = true:suggestion
+
+# Null-checking preferences
+csharp_style_conditional_delegate_call = true:suggestion
+
+# Modifier preferences
+csharp_prefer_static_local_function = true:suggestion
+csharp_preferred_modifier_order = public,private,protected,internal,file,static,extern,new,virtual,abstract,sealed,override,readonly,unsafe,required,volatile,async
+csharp_style_prefer_readonly_struct = true:suggestion
+csharp_style_prefer_readonly_struct_member = true:suggestion
+
+# Code-block preferences
+csharp_prefer_braces = true:silent
+csharp_prefer_simple_using_statement = true:suggestion
+csharp_style_namespace_declarations = file_scoped:silent
+csharp_style_prefer_method_group_conversion = true:silent
+csharp_style_prefer_primary_constructors = true:suggestion
+csharp_style_prefer_top_level_statements = true:silent
+
+# Expression-level preferences
+csharp_prefer_simple_default_expression = true:suggestion
+csharp_style_deconstructed_variable_declaration = true:suggestion
+csharp_style_implicit_object_creation_when_type_is_apparent = true:suggestion
+csharp_style_inlined_variable_declaration = true:suggestion
+csharp_style_prefer_index_operator = true:suggestion
+csharp_style_prefer_local_over_anonymous_function = true:suggestion
+csharp_style_prefer_null_check_over_type_check = true:suggestion
+csharp_style_prefer_range_operator = true:suggestion
+csharp_style_prefer_tuple_swap = true:suggestion
+csharp_style_prefer_utf8_string_literals = true:suggestion
+csharp_style_throw_expression = true:suggestion
+csharp_style_unused_value_assignment_preference = discard_variable:suggestion
+csharp_style_unused_value_expression_statement_preference = discard_variable:silent
+
+# 'using' directive preferences
+csharp_using_directive_placement = outside_namespace:silent
+
+# New line preferences
+csharp_style_allow_blank_line_after_colon_in_constructor_initializer_experimental = true:silent
+csharp_style_allow_blank_line_after_token_in_arrow_expression_clause_experimental = true:silent
+csharp_style_allow_blank_line_after_token_in_conditional_expression_experimental = true:silent
+csharp_style_allow_blank_lines_between_consecutive_braces_experimental = false:silent
+csharp_style_allow_embedded_statements_on_same_line_experimental = true:silent
+
+#### C# Formatting Rules ####
+
+# New line preferences
+csharp_new_line_before_catch = true
+csharp_new_line_before_else = true
+csharp_new_line_before_finally = true
+csharp_new_line_before_members_in_anonymous_types = true
+csharp_new_line_before_members_in_object_initializers = true
+csharp_new_line_before_open_brace = all
+csharp_new_line_between_query_expression_clauses = true
+
+# Indentation preferences
+csharp_indent_block_contents = true
+csharp_indent_braces = false
+csharp_indent_case_contents = true
+csharp_indent_case_contents_when_block = true
+csharp_indent_labels = one_less_than_current
+csharp_indent_switch_labels = true
+
+# Space preferences
+csharp_space_after_cast = false
+csharp_space_after_colon_in_inheritance_clause = true
+csharp_space_after_comma = true
+csharp_space_after_dot = false
+csharp_space_after_keywords_in_control_flow_statements = true
+csharp_space_after_semicolon_in_for_statement = true
+csharp_space_around_binary_operators = before_and_after
+csharp_space_around_declaration_statements = false
+csharp_space_before_colon_in_inheritance_clause = true
+csharp_space_before_comma = false
+csharp_space_before_dot = false
+csharp_space_before_open_square_brackets = false
+csharp_space_before_semicolon_in_for_statement = false
+csharp_space_between_empty_square_brackets = false
+csharp_space_between_method_call_empty_parameter_list_parentheses = false
+csharp_space_between_method_call_name_and_opening_parenthesis = false
+csharp_space_between_method_call_parameter_list_parentheses = false
+csharp_space_between_method_declaration_empty_parameter_list_parentheses = false
+csharp_space_between_method_declaration_name_and_open_parenthesis = false
+csharp_space_between_method_declaration_parameter_list_parentheses = false
+csharp_space_between_parentheses = false
+csharp_space_between_square_brackets = false
+
+# Wrapping preferences
+csharp_preserve_single_line_blocks = true
+csharp_preserve_single_line_statements = true
+
+#### Naming styles ####
+
+# Naming rules
+
+dotnet_naming_rule.interface_should_be_begins_with_i.severity = suggestion
+dotnet_naming_rule.interface_should_be_begins_with_i.symbols = interface
+dotnet_naming_rule.interface_should_be_begins_with_i.style = begins_with_i
+
+dotnet_naming_rule.types_should_be_pascal_case.severity = suggestion
+dotnet_naming_rule.types_should_be_pascal_case.symbols = types
+dotnet_naming_rule.types_should_be_pascal_case.style = pascal_case
+
+dotnet_naming_rule.non_field_members_should_be_pascal_case.severity = suggestion
+dotnet_naming_rule.non_field_members_should_be_pascal_case.symbols = non_field_members
+dotnet_naming_rule.non_field_members_should_be_pascal_case.style = pascal_case
+
+# Symbol specifications
+
+dotnet_naming_symbols.interface.applicable_kinds = interface
+dotnet_naming_symbols.interface.applicable_accessibilities = public, internal, private, protected, protected_internal, private_protected
+dotnet_naming_symbols.interface.required_modifiers = 
+
+dotnet_naming_symbols.types.applicable_kinds = class, struct, interface, enum
+dotnet_naming_symbols.types.applicable_accessibilities = public, internal, private, protected, protected_internal, private_protected
+dotnet_naming_symbols.types.required_modifiers = 
+
+dotnet_naming_symbols.non_field_members.applicable_kinds = property, event, method
+dotnet_naming_symbols.non_field_members.applicable_accessibilities = public, internal, private, protected, protected_internal, private_protected
+dotnet_naming_symbols.non_field_members.required_modifiers = 
+
+# Naming styles
+
+dotnet_naming_style.pascal_case.required_prefix = 
+dotnet_naming_style.pascal_case.required_suffix = 
+dotnet_naming_style.pascal_case.word_separator = 
+dotnet_naming_style.pascal_case.capitalization = pascal_case
+
+dotnet_naming_style.begins_with_i.required_prefix = I
+dotnet_naming_style.begins_with_i.required_suffix = 
+dotnet_naming_style.begins_with_i.word_separator = 
+dotnet_naming_style.begins_with_i.capitalization = pascal_case
+
+[*.{cs,vb}]
+dotnet_style_operator_placement_when_wrapping = beginning_of_line
+tab_width = 4
+indent_size = 4
+end_of_line = lf
+dotnet_style_coalesce_expression = true:suggestion
+dotnet_style_null_propagation = true:suggestion
+dotnet_style_prefer_is_null_check_over_reference_equality_method = true:suggestion
+dotnet_style_prefer_auto_properties = true:silent
+dotnet_style_object_initializer = true:suggestion
+dotnet_style_prefer_collection_expression = true:suggestion
+dotnet_style_collection_initializer = true:suggestion
+dotnet_style_prefer_simplified_boolean_expressions = true:suggestion
+dotnet_style_prefer_conditional_expression_over_assignment = true:silent
+dotnet_style_prefer_conditional_expression_over_return = true:silent
+dotnet_style_explicit_tuple_names = true:suggestion
+dotnet_style_prefer_inferred_tuple_names = true:suggestion
+dotnet_style_prefer_inferred_anonymous_type_member_names = true:suggestion
+dotnet_style_prefer_compound_assignment = true:suggestion
+dotnet_style_prefer_simplified_interpolation = true:suggestion
+dotnet_style_namespace_match_folder = true:suggestion
+indent_style = space
+insert_final_newline = true
+dotnet_style_readonly_field = true:suggestion
+dotnet_style_predefined_type_for_locals_parameters_members = true:silent
+dotnet_style_predefined_type_for_member_access = true:silent
+dotnet_style_require_accessibility_modifiers = for_non_interface_members:silent
+dotnet_style_allow_multiple_blank_lines_experimental = false:silent
+dotnet_style_allow_statement_immediately_after_block_experimental = false:silent
+dotnet_code_quality_unused_parameters = all:suggestion
+dotnet_style_parentheses_in_arithmetic_binary_operators = always_for_clarity:silent
+dotnet_style_parentheses_in_other_binary_operators = always_for_clarity:silent
+dotnet_style_parentheses_in_relational_binary_operators = always_for_clarity:silent
+dotnet_style_parentheses_in_other_operators = never_if_unnecessary:silent
+dotnet_style_qualification_for_field = false:silent
+dotnet_style_qualification_for_property = false:silent
+dotnet_style_qualification_for_method = false:silent
+dotnet_style_qualification_for_event = false:silent

AOC.Common/Day.cs

@@ -16,7 +16,7 @@ public abstract class Day(int year, int day, string puzzleName)
 
     public static bool UseTestInput { get; set; }
     private readonly Stopwatch _stopwatch = new();
-    
+
     public abstract void ProcessInput();
     public abstract object Part1();
     public abstract object Part2();

AOC.Common/Extensions.cs

@@ -31,8 +31,8 @@ public static class Extensions
             result[i] = new T[array.Length];
 
         for (var i = 0; i < array.Length; i++)
-        for (var j = 0; j < array[i].Length; j++)
-            result[i][j] = array[array.Length - j - 1][i];
+            for (var j = 0; j < array[i].Length; j++)
+                result[i][j] = array[array.Length - j - 1][i];
 
         return result;
     }

AOC.Common/Trees.cs

@@ -20,7 +20,7 @@ public class Tree<T>(Tree<T>.Node root)
     {
         public Node? Parent { get; private set; } = parent;
         public T Data { get; set; } = data;
-        private List<Node?> Children { get; } = new();
+        private List<Node?> Children { get; } = [];
 
         public Node? Left
         {

AOC.Test/Common.cs

@@ -6,14 +6,14 @@ public static class Common
     {
         Day.UseTestInput = testInput;
         var day = Activator.CreateInstance(dayType) as Day;
-        
+
         Assert.IsNotNull(day, "Failed to instantiate day object");
         Assert.IsTrue(File.Exists(day.FileName), $"File.Exists(day.FileName) {day.FileName}");
 
         var s = Stopwatch.StartNew();
         day.ProcessInput();
         s.Stop();
-        
+
         Console.WriteLine(
             $"{day.Year} Day {day.DayNumber,2}: {day.PuzzleName,-40} {s.ScaleMilliseconds()} ms elapsed processing input");
 

AOC.Test/Test2015.cs

@@ -7,7 +7,7 @@ public class Test2015
 {
     [DataTestMethod]
     [DataRow(typeof(Day01), "232", "1783")]
-    [DataRow(typeof(Day02),"1586300", "3737498")]
+    [DataRow(typeof(Day02), "1586300", "3737498")]
     [DataRow(typeof(Day03), "2081", "2341")]
     [DataRow(typeof(Day04), "346386", "9958218")]
     [DataRow(typeof(Day05), "258", "53")]

AOC.Test/Test2016.cs

@@ -16,7 +16,7 @@ public class Test2016
         █▒▒█▒▒██▒▒█▒▒█▒▒██▒▒▒██▒▒████▒▒██▒▒████▒▒███▒████▒
         
         """;
-    
+
     [DataTestMethod]
     [DataRow(typeof(Day01), "300", "159")]
     [DataRow(typeof(Day02), "76792", "A7AC3")]

AOC.Test/Test2023.cs

@@ -9,9 +9,9 @@ public class Test2023
     [DataRow(typeof(Day01), "54331", "54518")]
     public void CheckAllDays(Type dayType, string part1, string part2) =>
         Common.CheckDay(dayType, part1, part2);
-    
+
     [DataTestMethod]
     [DataRow(typeof(Day01), "142", "142")] // unfortunately p2 example is different
     public void CheckTestInputs(Type dayType, string part1, string part2) =>
         Common.CheckDay(dayType, part1, part2, true);
-}
+}

AOC2015/Day02.cs

@@ -7,19 +7,16 @@ public sealed class Day02() : Day(2015, 2, "I Was Told There Would Be No Math")
 {
     private List<List<int>>? _gifts;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _gifts = Input.Select(line => line.Split('x').Select(int.Parse).ToList()).ToList();
-    }
 
-    public override object Part1()
-    {
-        return _gifts!.Sum(gift =>
+    public override object Part1() =>
+        _gifts!.Sum(gift =>
         {
             var biggestDimension = gift.IndexOf(gift.Max());
 
             var surfaceArea = 2 * gift[0] * gift[1] + 2 * gift[1] * gift[2] + 2 * gift[0] * gift[2];
-            
+
             var smallestSideArea = 1;
             for (var i = 0; i < gift.Count; i++)
             {
@@ -29,11 +26,9 @@ public sealed class Day02() : Day(2015, 2, "I Was Told There Would Be No Math")
 
             return surfaceArea + smallestSideArea;
         });
-    }
 
-    public override object Part2()
-    {
-        return _gifts!.Sum(gift =>
+    public override object Part2() =>
+        _gifts!.Sum(gift =>
         {
             var biggestDimension = gift.IndexOf(gift.Max());
             var bowArea = gift.Aggregate(1, (i, i1) => i * i1);
@@ -47,6 +42,4 @@ public sealed class Day02() : Day(2015, 2, "I Was Told There Would Be No Math")
 
             return smallestSide + bowArea;
         });
-    }
 }
-

AOC2015/Day03.cs

@@ -12,7 +12,7 @@ public sealed class Day03() : Day(2015, 3, "Perfectly Spherical Houses in a Vacu
     public override object Part1()
     {
         int x = 0, y = 0;
-         Dictionary<(int x, int y), int> map = new() { [(0, 0)] = 1 };
+        Dictionary<(int x, int y), int> map = new() { [(0, 0)] = 1 };
 
         foreach (var c in Input.First())
         {

AOC2015/Day04.cs

@@ -9,10 +9,7 @@ public sealed class Day04() : Day(2015, 4, "The Ideal Stocking Stuffer")
 {
     private string? _key;
 
-    public override void ProcessInput()
-    {
-        _key = Input.First();
-    }
+    public override void ProcessInput() => _key = Input.First();
 
     public override object Part1()
     {

AOC2015/Day05.cs

@@ -5,8 +5,8 @@ namespace AOC2015;
 /// </summary>
 public sealed partial class Day05() : Day(2015, 5, "Doesn't He Have Intern-Elves For This?")
 {
-    private static readonly List<char> Vowels = new() { 'a', 'e', 'i', 'o', 'u' };
-    private List<string> _strings = new();
+    private static readonly List<char> Vowels = ['a', 'e', 'i', 'o', 'u'];
+    private List<string> _strings = [];
 
     [GeneratedRegex(@"(.)\1")]
     private static partial Regex DoubleLetter();
@@ -17,10 +17,8 @@ public sealed partial class Day05() : Day(2015, 5, "Doesn't He Have Intern-Elves
     [GeneratedRegex(@"(..).*\1")]
     private static partial Regex TwoPairs();
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _strings = Input.Where(line => !string.IsNullOrEmpty(line)).ToList();
-    }
 
     public override object Part1() =>
         _strings.Count(s =>

AOC2015/Day06.cs

@@ -5,8 +5,8 @@ namespace AOC2015;
 /// </summary>
 public sealed partial class Day06() : Day(2015, 6, "Probably a Fire Hazard")
 {
-    private readonly Dictionary<(int x, int y), int> _brightnessGrid = new();
-    private readonly Dictionary<(int x, int y), bool> _lightGrid = new();
+    private readonly Dictionary<(int x, int y), int> _brightnessGrid = [];
+    private readonly Dictionary<(int x, int y), bool> _lightGrid = [];
 
     [GeneratedRegex(@"(\d+),(\d+) through (\d+),(\d+)")]
     private static partial Regex Coords();

AOC2015/Day07.cs

@@ -5,8 +5,8 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day07() : Day(2015, 7, "Some Assembly Required")
 {
-    private readonly Dictionary<string, Func<ushort>> _actions = new();
-    private readonly Dictionary<string, ushort> _wires = new();
+    private readonly Dictionary<string, Func<ushort>> _actions = [];
+    private readonly Dictionary<string, ushort> _wires = [];
 
     public override void ProcessInput()
     {

AOC2015/Day09.cs

@@ -5,7 +5,7 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day09() : Day(2015, 9, "All in a Single Night")
 {
-    private readonly List<Distance> _distances = new();
+    private readonly List<Distance> _distances = [];
     private int _shortest = int.MaxValue, _longest;
 
     public override void ProcessInput()

AOC2015/Day10.cs

@@ -7,10 +7,7 @@ public sealed class Day10() : Day(2015, 10, "Elves Look, Elves Say")
 {
     private string? _seed;
 
-    public override void ProcessInput()
-    {
-        _seed = Input.First();
-    }
+    public override void ProcessInput() => _seed = Input.First();
 
     public override object Part1()
     {

AOC2015/Day11.cs

@@ -7,10 +7,7 @@ public sealed class Day11() : Day(2015, 11, "Corporate Policy")
 {
     private char[]? _password;
 
-    public override void ProcessInput()
-    {
-        _password = Input.First().ToCharArray();
-    }
+    public override void ProcessInput() => _password = Input.First().ToCharArray();
 
     public override object Part1()
     {

AOC2015/Day13.cs

@@ -5,8 +5,8 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day13() : Day(2015, 13, "Knights of the Dinner Table")
 {
-    private readonly Dictionary<(string person1, string person2), int> _happinessMap = new();
-    private readonly List<string> _people = new();
+    private readonly Dictionary<(string person1, string person2), int> _happinessMap = [];
+    private readonly List<string> _people = [];
 
     public override void ProcessInput()
     {
@@ -55,7 +55,7 @@ public sealed class Day13() : Day(2015, 13, "Knights of the Dinner Table")
                 (item, permutation) => new[] { item }.Concat(permutation).ToList()).ToList();
         }
 
-        return new() { items };
+        return [items];
     }
 
     private long ComputeHappiness()

AOC2015/Day14.cs

@@ -7,10 +7,7 @@ public sealed class Day14() : Day(2015, 14, "Reindeer Olympics")
 {
     private List<Reindeer>? _reindeer;
 
-    public override void ProcessInput()
-    {
-        _reindeer = Input.Select(i => new Reindeer(i)).ToList();
-    }
+    public override void ProcessInput() => _reindeer = Input.Select(i => new Reindeer(i)).ToList();
 
     public override object Part1() =>
         _reindeer!.Select(r => r.Fly(2503)).Max();
@@ -21,12 +18,14 @@ public sealed class Day14() : Day(2015, 14, "Reindeer Olympics")
             .GroupBy(r => r)
             .Max(g => g.Count());
 
-    private class Reindeer {
+    private class Reindeer
+    {
         private readonly int _duration;
         private readonly int _rest;
         private readonly int _speed;
 
-        public Reindeer(string input) {
+        public Reindeer(string input)
+        {
             var p = input.Split(' ');
             _speed = int.Parse(p[3]);
             _duration = int.Parse(p[6]);

AOC2015/Day16.cs

@@ -9,9 +9,8 @@ public sealed class Day16() : Day(2015, 16, "Aunt Sue")
     {
     }
 
-    private IEnumerable<string> Common()
-    {
-        return Input
+    private IEnumerable<string> Common() =>
+        Input
             .Select(i => Regex.Replace(i, @": \d\d", ": 9"))
             .WhereMatch("children: 3")
             .WhereMatch("samoyeds: 2")
@@ -19,33 +18,28 @@ public sealed class Day16() : Day(2015, 16, "Aunt Sue")
             .WhereMatch("vizslas: 0")
             .WhereMatch("cars: 2")
             .WhereMatch("perfumes: 1");
-    }
 
-    public override object Part1()
-    {
-        return Common()
+    public override object Part1() =>
+        Common()
             .WhereMatch("cats: 7")
             .WhereMatch("trees: 3")
             .WhereMatch("pomeranians: 3")
             .WhereMatch("goldfish: 5")
             .Single()
             .Split(' ', ':')[1];
-    }
 
-    public override object Part2()
-    {
-        return Common()
+    public override object Part2() =>
+        Common()
             .WhereMatch("cats: [89]")
             .WhereMatch("trees: [4-9]")
             .WhereMatch("pomeranians: [012]")
             .WhereMatch("goldfish: [0-4]")
             .Single()
             .Split(' ', ':')[1];
-    }
 }
 
 public static class Day16Extensions
 {
     public static IEnumerable<string> WhereMatch(this IEnumerable<string> input, string pattern) =>
         input.Where(i => !i.Contains(pattern.Split(' ')[0]) || Regex.IsMatch(i, pattern));
-}
+}

AOC2015/Day19.cs

@@ -31,7 +31,7 @@ public sealed class Day19() : Day(2015, 19, "Medicine for Rudolph")
 
     public override object Part1()
     {
-        HashSet<string> compounds = new();
+        HashSet<string> compounds = [];
         foreach (var rule in _rules!)
             foreach (var match in Regex.EnumerateMatches(_compound, rule[0]))
                 compounds.Add(_compound!.Remove(match.Index, rule[0].Length).Insert(match.Index, rule[1]));

AOC2015/Day20.cs

@@ -7,10 +7,8 @@ public sealed class Day20() : Day(2015, 20, "Infinite Elves and Infinite Houses"
 {
     private int _input;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _input = int.Parse(Input.First());
-    }
 
     public override object Part1()
     {

AOC2015/Day21.cs

@@ -63,12 +63,12 @@ public sealed class Day21() : Day(2015, 21, "RPG Simulator 20XX")
 
     private bool StillAlive(Combination combination)
     {
-        var myDamage          = Math.Max(combination.TotalDamage - _boss!["Armor"], 1);
+        var myDamage = Math.Max(combination.TotalDamage - _boss!["Armor"], 1);
         var bossDamagePerTurn = Math.Max(_boss["Damage"] - combination.TotalArmor, 1);
 
         var turnsToLose = PlayerHp / bossDamagePerTurn;
         if (PlayerHp % bossDamagePerTurn > 0) turnsToLose++;
-        
+
         var turnsToKillBoss = _boss["Hit Points"] / myDamage;
         if (_boss["Hit Points"] % myDamage > 0) turnsToKillBoss++;
 

AOC2015/Day22.cs

@@ -7,19 +7,26 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day22() : Day(2015, 22, "Wizard Simulator 20XX")
 {
-    private static readonly List<Spell> Spells = new()
-    {
+    private static readonly List<Spell> Spells =
+    [
         new("Magic Missile", Mana: 53, Damage: 4),
         new("Drain", Mana: 73, Damage: 2, Heal: 2),
         new("Shield", Mana: 113, Armor: 7, Duration: 6),
         new("Poison", Mana: 173, Damage: 3, Duration: 6),
         new("Recharge", Mana: 229, ManaCharge: 101, Duration: 5)
-    };
+    ];
 
     private Dictionary<string, int> _boss;
 
-    public record Spell(string Name, int Mana, int Duration = 0, int Damage = 0, int Heal = 0, int Armor = 0,
-        int ManaCharge = 0);
+    public record Spell(
+        string Name,
+        int Mana,
+        int Duration = 0,
+        int Damage = 0,
+        int Heal = 0,
+        int Armor = 0,
+        int ManaCharge = 0
+    );
 
     public struct GameState(bool HardMode = false, int RoundNumber = 0, int TotalManaSpent = 0, int PlayerHealth = 50,
         int PlayerMana = 500, int BossHealth = 0, int BossDamage = 0, Dictionary<Spell, int>? ActiveSpells = null)
@@ -92,15 +99,11 @@ public sealed class Day22() : Day(2015, 22, "Wizard Simulator 20XX")
         return initialState;
     }
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _boss = Input.ToDictionary(k => k.Split(": ")[0], v => int.Parse(v.Split(": ")[1]));
-    }
 
-    public override object Part1()
-    {
-        return ProcessStates(new(BossHealth: _boss["Hit Points"], BossDamage: _boss["Damage"]));
-    }
+    public override object Part1() =>
+        ProcessStates(new(BossHealth: _boss["Hit Points"], BossDamage: _boss["Damage"]));
 
     public override object Part2() => "";
-}
+}

AOC2016/Day01.cs

@@ -7,10 +7,7 @@ public sealed class Day01() : Day(2016, 1, "No Time for a Taxicab")
 {
     private string[]? _moves;
 
-    public override void ProcessInput()
-    {
-        _moves = Input.First().Split(", ");
-    }
+    public override void ProcessInput() => _moves = Input.First().Split(", ");
 
     private enum Direction
     {
@@ -20,9 +17,8 @@ public sealed class Day01() : Day(2016, 1, "No Time for a Taxicab")
         West,
     }
 
-    private static Direction Turn(Direction current, char newDirection)
-    {
-        return current switch
+    private static Direction Turn(Direction current, char newDirection) =>
+        current switch
         {
             Direction.North => newDirection == 'L' ? Direction.West : Direction.East,
             Direction.South => newDirection == 'L' ? Direction.East : Direction.West,
@@ -30,11 +26,9 @@ public sealed class Day01() : Day(2016, 1, "No Time for a Taxicab")
             Direction.West => newDirection == 'L' ? Direction.South : Direction.North,
             _ => throw new ArgumentException("invalid direction", nameof(current)),
         };
-    }
 
-    private static (int x, int y) Move((int x, int y) coord, Direction direction)
-    {
-        return direction switch
+    private static (int x, int y) Move((int x, int y) coord, Direction direction) =>
+        direction switch
         {
             Direction.North => (coord.x, coord.y + 1),
             Direction.South => (coord.x, coord.y - 1),
@@ -42,7 +36,6 @@ public sealed class Day01() : Day(2016, 1, "No Time for a Taxicab")
             Direction.West => (coord.x - 1, coord.y),
             _ => (0, 0)
         };
-    }
 
     public override object Part1()
     {
@@ -61,7 +54,7 @@ public sealed class Day01() : Day(2016, 1, "No Time for a Taxicab")
 
     public override object Part2()
     {
-        HashSet<(int x, int y)> visitedLocations = new();
+        HashSet<(int x, int y)> visitedLocations = [];
         var direction = Direction.North;
         var location = (x: 0, y: 0);
 

AOC2016/Day02.cs

@@ -11,7 +11,7 @@ public sealed class Day02() : Day(2016, 2, "Bathroom Security")
 
     public override object Part1()
     {
-        List<int> answer = new();
+        List<int> answer = [];
         var location = (x: 1, y: 1);
 
         foreach (var line in Input)
@@ -42,7 +42,7 @@ public sealed class Day02() : Day(2016, 2, "Bathroom Security")
             { '\0', '\0', 'D', '\0', '\0' },
         };
         var location = (x: 0, y: 2);
-        List<char> answer = new();
+        List<char> answer = [];
 
         foreach (var line in Input)
         {
@@ -60,4 +60,4 @@ public sealed class Day02() : Day(2016, 2, "Bathroom Security")
 
         return string.Join("", answer);
     }
-}
+}

AOC2016/Day03.cs

@@ -7,22 +7,19 @@ public sealed class Day03() : Day(2016, 3, "Squares With Three Sides")
 {
     private List<int[]> _triangles = null!;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _triangles = Input
             .Select(line => line.Split(' ', StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries)
                 .Select(int.Parse).ToArray())
             .ToList();
-    }
 
-    public override object Part1() => _triangles.Count(ValidTriangle);
+    public override object Part1() =>
+        _triangles.Count(ValidTriangle);
 
-    private static bool ValidTriangle(params int[] triangle)
-    {
-        return triangle[0] + triangle[1] > triangle[2] &&
-               triangle[0] + triangle[2] > triangle[1] &&
-               triangle[1] + triangle[2] > triangle[0];
-    }
+    private static bool ValidTriangle(params int[] triangle) =>
+        triangle[0] + triangle[1] > triangle[2] &&
+        triangle[0] + triangle[2] > triangle[1] &&
+        triangle[1] + triangle[2] > triangle[0];
 
     public override object Part2()
     {
@@ -36,4 +33,4 @@ public sealed class Day03() : Day(2016, 3, "Squares With Three Sides")
 
         return cnt;
     }
-}
+}

AOC2016/Day04.cs

@@ -29,19 +29,19 @@ public sealed class Day04() : Day(2016, 4, "Security Through Obscurity")
         {
             var answer = Name.ToCharArray();
             for (var i = 0; i < Name.Length; i++)
-            for (var l = 0; l < SectorId % 26; l++)
-                answer[i] = answer[i] == 'z' ? 'a' : (char)(answer[i] + 1);
+                for (var l = 0; l < SectorId % 26; l++)
+                    answer[i] = answer[i] == 'z' ? 'a' : (char)(answer[i] + 1);
 
             return new(answer);
         }
     }
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _rooms = Input.Select(Room.FromRawLine).ToList();
-    }
 
-    public override object Part1() => _rooms.Where(r => r.IsRealRoom()).Sum(r => r.SectorId);
+    public override object Part1() =>
+        _rooms.Where(r => r.IsRealRoom()).Sum(r => r.SectorId);
 
-    public override object Part2() => _rooms.Single(r => r.DecryptedName().Contains("northpole")).SectorId;
-}
+    public override object Part2() =>
+        _rooms.Single(r => r.DecryptedName().Contains("northpole")).SectorId;
+}

AOC2016/Day06.cs

@@ -7,10 +7,7 @@ public sealed class Day06() : Day(2016, 6, "Signals and Noise")
 {
     private List<string>? _input;
 
-    public override void ProcessInput()
-    {
-        _input = Input.ToList();
-    }
+    public override void ProcessInput() => _input = Input.ToList();
 
     public override object Part1()
     {

AOC2016/Day07.cs

@@ -41,10 +41,10 @@ public sealed partial class Day07() : Day(2016, 7, "Internet Protocol Version 7"
     private static bool SupportsSsl(string input)
     {
         foreach (var ip in BracketsRegex().Split(input))
-        foreach (var aba in CheckAba(ip))
-        foreach (var m in InsideBracketsRegex().Matches(input).Cast<Match>())
-            if (m.Value.Contains($"{aba[1]}{aba[0]}{aba[1]}"))
-                return true;
+            foreach (var aba in CheckAba(ip))
+                foreach (var m in InsideBracketsRegex().Matches(input).Cast<Match>())
+                    if (m.Value.Contains($"{aba[1]}{aba[0]}{aba[1]}"))
+                        return true;
 
         return false;
     }

AOC2016/Day08.cs

@@ -54,14 +54,12 @@ public sealed class Day08() : Day(2016, 8, "Two-Factor Authentication")
         }
     }
 
-    public override object Part1()
-    {
-        return Input.Where(line => line.StartsWith("rect")).Sum(rect =>
+    public override object Part1() =>
+        Input.Where(line => line.StartsWith("rect")).Sum(rect =>
         {
             var s = rect.Split('x', ' ').Skip(1).Select(int.Parse).ToList();
             return s[0] * s[1];
         });
-    }
 
     public override object Part2()
     {
@@ -94,4 +92,4 @@ public sealed class Day08() : Day(2016, 8, "Two-Factor Authentication")
 
         return Environment.NewLine + PrintGrid(screen);
     }
-}
+}

AOC2016/Day22.cs

@@ -8,7 +8,7 @@ public sealed class Day22() : Day(2016, 22, "Puzzle Name")
     public override void ProcessInput()
     {
     }
-    
+
     public override object Part1() => "";
 
     public override object Part2() => "";

AOC2018/Day02.cs

@@ -26,8 +26,8 @@ public sealed class Day02() : Day(2018, 2, "Inventory Management System")
         var input = Input.ToImmutableList();
 
         foreach (var id1 in input)
-        foreach (var id2 in input.Where(line2 => id1.HammingDistance(line2) == 1))
-            return id1.Remove(id1.Zip(id2).Indexed().First(i => i.Value.First != i.Value.Second).Key, 1);
+            foreach (var id2 in input.Where(line2 => id1.HammingDistance(line2) == 1))
+                return id1.Remove(id1.Zip(id2).Indexed().First(i => i.Value.First != i.Value.Second).Key, 1);
 
         throw new("Correct IDs not found");
     }

AOC2018/Day03.cs

@@ -6,26 +6,26 @@ namespace AOC2018;
 public sealed partial class Day03() : Day(2018, 3, "No Matter How You Slice It")
 {
     private List<Claim>? _claims;
-    private readonly Dictionary<(int x, int y), List<int>> _plots = new();
+    private readonly Dictionary<(int x, int y), List<int>> _plots = [];
 
     [GeneratedRegex(@"\d+")]
     private static partial Regex Digits();
 
     private record Claim(int ID, int X, int Y, int SizeX, int SizeY);
-    
+
     public override void ProcessInput()
     {
         _claims = Input.Select(line => Digits().Matches(line).Select(m => int.Parse(m.Value)).ToList())
             .Select(l => new Claim(l[0], l[1], l[2], l[3], l[4])).ToList();
-        
+
         foreach (var claim in _claims)
         {
             foreach (var y in Enumerable.Range(claim.X, claim.SizeX))
-            foreach (var x in Enumerable.Range(claim.Y, claim.SizeY))
-            {
-                if (!_plots.ContainsKey((x, y))) _plots.Add((x, y), new());
-                _plots[(x, y)].Add(claim.ID);
-            }
+                foreach (var x in Enumerable.Range(claim.Y, claim.SizeY))
+                {
+                    if (!_plots.ContainsKey((x, y))) _plots.Add((x, y), []);
+                    _plots[(x, y)].Add(claim.ID);
+                }
         }
     }
 

AOC2019/Day01.cs

@@ -4,10 +4,8 @@ public sealed class Day01() : Day(2019, 1, "The Tyranny of the Rocket Equation")
 {
     private IEnumerable<int>? _masses;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _masses = Input.Select(int.Parse);
-    }
 
     private static int FuelCost(int weight) => weight / 3 - 2;
 

AOC2019/Day02.cs

@@ -4,10 +4,8 @@ public sealed class Day02() : Day(2019, 2, "1202 Program Alarm")
 {
     private IEnumerable<int>? _input;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _input = Input.First().Split(',').Select(int.Parse);
-    }
 
     private int RunIntCode(int noun, int verb)
     {
@@ -26,10 +24,7 @@ public sealed class Day02() : Day(2019, 2, "1202 Program Alarm")
         return v[0];
     }
 
-    public override object Part1()
-    {
-        return RunIntCode(12, 2);
-    }
+    public override object Part1() => RunIntCode(12, 2);
 
     public override object Part2()
     {

AOC2019/Day05.cs

@@ -5,20 +5,15 @@ public sealed class Day05() : Day(2019, 5, "Sunny with a Chance of Asteroids")
     private IEnumerable<int>? _tape;
     private int _output;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _tape = Input.First().Split(',').Select(int.Parse);
-    }
 
     private void RunIntCode(IList<int> v, int input)
     {
         var i = 0;
         while (i < v.Count && v[i] != 99)
         {
-            int Val(int mode, int val)
-            {
-                return mode != 0 ? val : v[val];
-            }
+            int Val(int mode, int val) => mode != 0 ? val : v[val];
 
             var mode1 = v[i] / 100 % 10;
             var mode2 = v[i] / 1000;
@@ -70,4 +65,4 @@ public sealed class Day05() : Day(2019, 5, "Sunny with a Chance of Asteroids")
         RunIntCode(_tape!.ToList(), 5);
         return _output;
     }
-}
+}

AOC2019/Day06.cs

@@ -4,16 +4,14 @@ public sealed class Day06() : Day(2019, 6, "Universal Orbit Map")
 {
     private Dictionary<string, string>? _input;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _input = Input.ToDictionary(i => i.Split(')')[1], i => i.Split(')')[0]);
-    }
 
     private List<string> GetParents(string obj)
     {
         var res = new List<string>();
-        for (var curr = obj; curr != "COM"; curr = _input![curr])
-            res.Add(curr);
+        for (var current = obj; current != "COM"; current = _input![current])
+            res.Add(current);
         res.Add("COM");
         return res;
     }
@@ -32,4 +30,4 @@ public sealed class Day06() : Day(2019, 6, "Universal Orbit Map")
 
         return you.Count + san.Count - common * 2;
     }
-}
+}

AOC2019/Day08.cs

@@ -4,10 +4,8 @@ public sealed class Day08() : Day(2019, 8, "Space Image Format")
 {
     private List<List<char>>? _photo;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _photo = Input.First().Chunk(25 * 6).Select(s => s.ToList()).ToList();
-    }
 
     public override object Part1()
     {
@@ -15,9 +13,8 @@ public sealed class Day08() : Day(2019, 8, "Space Image Format")
         return l.Count(p => p == '1') * l.Count(p => p == '2');
     }
 
-    public override object Part2()
-    {
-        return Enumerable.Range(0, 25 * 6)
+    public override object Part2() =>
+        Enumerable.Range(0, 25 * 6)
             .Select(p => Enumerable.Range(0, _photo!.Count)
                 .Select(l => _photo[l][p])
                 .Aggregate('2', (acc, next) =>
@@ -29,5 +26,4 @@ public sealed class Day08() : Day(2019, 8, "Space Image Format")
             .Select(s => new string(s).Trim())
             .ToDelimitedString(Environment.NewLine)
             .Replace('1', 'x');
-    }
-}
+}

AOC2019/Day09.cs

@@ -4,10 +4,8 @@ public sealed class Day09() : Day(2019, 9, "Sensor Boost")
 {
     private IntCodeVM? _vm;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _vm = new(Input.First());
-    }
 
     public override object Part1()
     {
@@ -22,4 +20,4 @@ public sealed class Day09() : Day(2019, 9, "Sensor Boost")
         _vm.Run(2);
         return _vm.Output.ToDelimitedString(",");
     }
-}
+}

AOC2019/Day10.cs

@@ -6,15 +6,13 @@ public sealed class Day10() : Day(2019, 10, "Monitoring Station")
     private (int x, int y) _best = (x: -1, y: -1);
     private int _bestCanSee;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _asteroids = Input
             .Select((r, y) => r.Select((c, x) => (x, y, isAsteroid: c == '#')).ToArray())
             .SelectMany(r => r)
             .Where(a => a.isAsteroid)
             .Select(a => (a.x, a.y))
             .ToHashSet();
-    }
 
     public override object Part1()
     {
@@ -63,4 +61,4 @@ public sealed class Day10() : Day(2019, 10, "Monitoring Station")
             .Select(a => a.x * 100 + a.y)
             .Single();
     }
-}
+}

AOC2019/Day11.cs

@@ -6,11 +6,17 @@ public sealed class Day11() : Day(2019, 11, "Space Police")
     private Direction _heading;
     private long _x, _y;
 
-    public override void ProcessInput()
+    private enum Direction
     {
-        _vm = new(Input.First());
+        Up,
+        Down,
+        Left,
+        Right
     }
 
+    public override void ProcessInput() =>
+        _vm = new(Input.First());
+
     private void Move()
     {
         switch (_heading)
@@ -36,9 +42,9 @@ public sealed class Day11() : Day(2019, 11, "Space Police")
     {
         _heading = _heading switch
         {
-            Direction.Up    => direction == 0 ? Direction.Left : Direction.Right,
-            Direction.Down  => direction == 0 ? Direction.Right : Direction.Left,
-            Direction.Left  => direction == 0 ? Direction.Down : Direction.Up,
+            Direction.Up => direction == 0 ? Direction.Left : Direction.Right,
+            Direction.Down => direction == 0 ? Direction.Right : Direction.Left,
+            Direction.Left => direction == 0 ? Direction.Down : Direction.Up,
             Direction.Right => direction == 0 ? Direction.Up : Direction.Down,
             _ => _heading
         };
@@ -85,12 +91,4 @@ public sealed class Day11() : Day(2019, 11, "Space Police")
             .Reverse()
             .ToDelimitedString(Environment.NewLine);
     }
-
-    private enum Direction
-    {
-        Up,
-        Down,
-        Left,
-        Right
-    }
 }

AOC2019/Day12.cs

@@ -58,9 +58,9 @@ public sealed class Day12() : Day(2019, 12, "The N-Body Problem")
 
     public class Position(IList<int> moon)
     {
-        private List<Position> _siblings = new();
+        private List<Position> _siblings = [];
         private int _x = moon[0], _y = moon[1], _z = moon[2];
-        public int Dx = 0, Dy = 0, Dz = 0;
+        public int Dx, Dy, Dz;
 
         private int KineticEnergy =>
             Math.Abs(_x) + Math.Abs(_y) + Math.Abs(_z);
@@ -94,4 +94,4 @@ public sealed class Day12() : Day(2019, 12, "The N-Body Problem")
             _z += Dz;
         }
     }
-}
+}

AOC2019/Day13.cs

@@ -3,13 +3,11 @@ namespace AOC2019;
 public sealed class Day13() : Day(2019, 13, "Care Package")
 {
     private IntCodeVM? _vm;
-    private readonly Dictionary<(long x, long y), long> _board = new();
-    private readonly List<(long x, long y)> _updatedCoordinates = new();
+    private readonly Dictionary<(long x, long y), long> _board = [];
+    private readonly List<(long x, long y)> _updatedCoordinates = [];
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _vm = new(Input.First());
-    }
 
     private void PrintBoard()
     {
@@ -64,7 +62,7 @@ public sealed class Day13() : Day(2019, 13, "Care Package")
 
             if (printBoard) PrintBoard();
 
-            var (ball, _)   = _board.Single(t => t.Value == 4).Key;
+            var (ball, _) = _board.Single(t => t.Value == 4).Key;
             var (paddle, _) = _board.Single(t => t.Value == 3).Key;
             _vm.AddInput(Math.Sign(ball.CompareTo(paddle)));
 
@@ -73,4 +71,4 @@ public sealed class Day13() : Day(2019, 13, "Care Package")
 
         return $"after {gameTicks} moves, the score is: {_board[(-1, 0)]}";
     }
-}
+}

AOC2019/Day14.cs

@@ -3,14 +3,12 @@ namespace AOC2019;
 public sealed class Day14() : Day(2019, 14, "Space Stoichiometry")
 {
     private Dictionary<string, Reaction>? _reactions;
-    private Dictionary<string, long> _available = new();
+    private Dictionary<string, long> _available = [];
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _reactions = Input
             .Select(Reaction.Parse)
             .ToDictionary(r => r.Product.Name);
-    }
 
     private bool Consume(string chem, long quantity)
     {

AOC2019/Day15.cs

@@ -2,13 +2,11 @@ namespace AOC2019;
 
 public sealed class Day15() : Day(2019, 15, "Oxygen System")
 {
-    private readonly bool _verbose = false;
+    private const bool Verbose = false;
     private IntCodeVM? _vm;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _vm = new(Input.First());
-    }
 
     public override object Part1()
     {
@@ -54,7 +52,7 @@ public sealed class Day15() : Day(2019, 15, "Oxygen System")
                 }
                 else
                 {
-                    if (_verbose)
+                    if (Verbose)
                     {
                         // find extents of canvas
                         int yMin, yMax;
@@ -125,7 +123,7 @@ public sealed class Day15() : Day(2019, 15, "Oxygen System")
         private static readonly int[] Dy = { 0, 1, -1, 0, 0 };
         public static readonly int[] Opposites = { 0, 2, 1, 4, 3 };
 
-        public static readonly Dictionary<(int x, int y), Location> AllLocations = new();
+        public static readonly Dictionary<(int x, int y), Location> AllLocations = [];
 
         private readonly int _currentType;
 
@@ -156,16 +154,13 @@ public sealed class Day15() : Day(2019, 15, "Oxygen System")
 
         public bool IsWall => _currentType == Wall;
 
-        public string Image()
+        public string Image() => _currentType switch
         {
-            return _currentType switch
-            {
-                Wall => "\u2587",
-                Empty => X == 0 && Y == 0 ? "S" : " ",
-                System => "O",
-                _ => "?"
-            };
-        }
+            Wall => "\u2587",
+            Empty => X == 0 && Y == 0 ? "S" : " ",
+            System => "O",
+            _ => "?"
+        };
 
         public bool UpdateDistanceToOxygenSystem()
         {
@@ -184,29 +179,14 @@ public sealed class Day15() : Day(2019, 15, "Oxygen System")
             return false;
         }
 
-        public (int, int) Neighbor(int direction)
-        {
-            return (X + Dx[direction], Y + Dy[direction]);
-        }
+        public (int, int) Neighbor(int direction) => (X + Dx[direction], Y + Dy[direction]);
 
-        public (int, int) PreviousLocation()
-        {
-            return Neighbor(PreviousDirection);
-        }
+        public (int, int) PreviousLocation() => Neighbor(PreviousDirection);
 
-        public int NextDirection()
-        {
-            return _searchDirection++;
-        }
+        public int NextDirection() => _searchDirection++;
 
-        public static Location? GetLocation(int x, int y)
-        {
-            return AllLocations.ContainsKey((x, y)) ? AllLocations[(x, y)] : null;
-        }
+        public static Location? GetLocation(int x, int y) => AllLocations.ContainsKey((x, y)) ? AllLocations[(x, y)] : null;
 
-        public static Location? GetLocation((int x, int y) coords)
-        {
-            return GetLocation(coords.x, coords.y);
-        }
+        public static Location? GetLocation((int x, int y) coords) => GetLocation(coords.x, coords.y);
     }
 }

AOC2019/Day16.cs

@@ -5,10 +5,8 @@ public sealed class Day16() : Day(2019, 16, "Flawed Frequency Transmission")
     private static readonly int[] BasePattern = { 0, 1, 0, -1 };
     private int[]? _initialList;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _initialList = Input.First().Select(c => c - '0').ToArray();
-    }
 
     public override object Part1()
     {
@@ -49,4 +47,4 @@ public sealed class Day16() : Day(2019, 16, "Flawed Frequency Transmission")
                 .Take(input.Length)
                 .Select((pv, i) => pv * input[i] % 10).Sum()) % 10;
     }
-}
+}

AOC2019/Day17.cs

@@ -4,10 +4,8 @@ public sealed class Day17() : Day(2019, 17, "Set and Forget")
 {
     private IntCodeVM? _vm;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _vm = new(Input.First());
-    }
 
     public override object Part1()
     {
@@ -21,19 +19,18 @@ public sealed class Day17() : Day(2019, 17, "Set and Forget")
 
         var sum = 0;
         for (var y = 1; y < grid.Length - 1; y++)
-        for (var x = 1; x < grid[y].Length - 1; x++)
-            if (grid[y][x] == '#' &&
-                grid[y - 1][x] == '#' &&
-                grid[y + 1][x] == '#' &&
-                grid[y][x - 1] == '#' &&
-                grid[y][x + 1] == '#')
-                sum += x * y;
+            for (var x = 1; x < grid[y].Length - 1; x++)
+                if (grid[y][x] == '#' &&
+                    grid[y - 1][x] == '#' &&
+                    grid[y + 1][x] == '#' &&
+                    grid[y][x - 1] == '#' &&
+                    grid[y][x + 1] == '#')
+                    sum += x * y;
 
         return sum;
     }
 
-    public override object Part2()
-    {
+    public override object Part2() =>
         //vm.Reset();
         //vm.memory[0] = 2;
         //var halt = IntCodeVM.HaltType.Waiting;
@@ -41,6 +38,5 @@ public sealed class Day17() : Day(2019, 17, "Set and Forget")
         //{
         //    halt = vm.Run();
         //}
-        return "";
-    }
+        "";
 }

AOC2019/Day18.cs

@@ -6,13 +6,7 @@ public sealed class Day18() : Day(2019, 18, "Many-Worlds Interpretation")
     {
     }
 
-    public override object Part1()
-    {
-        return "";
-    }
+    public override object Part1() => "";
 
-    public override object Part2()
-    {
-        return "";
-    }
+    public override object Part2() => "";
 }

AOC2019/Day19.cs

@@ -5,7 +5,8 @@ public sealed class Day19() : Day(2019, 19, "Tractor Beam")
     private long[,]? _grid;
     private IntCodeVM? _vm;
 
-    public override void ProcessInput(){
+    public override void ProcessInput()
+    {
         _vm = new(Input.First());
         _grid = new long[50, 50];
     }

AOC2019/Day20.cs

@@ -6,13 +6,7 @@ public sealed class Day20() : Day(2019, 20, "Donut Maze")
     {
     }
 
-    public override object Part1()
-    {
-        return "";
-    }
+    public override object Part1() => "";
 
-    public override object Part2()
-    {
-        return "";
-    }
+    public override object Part2() => "";
 }

AOC2019/Day21.cs

@@ -4,11 +4,9 @@ public sealed class Day21 : Day
 {
     private readonly IntCodeVM _vm;
 
-    public Day21() : base(2019, 21, "Springdroid Adventure")
-    {
+    public Day21() : base(2019, 21, "Springdroid Adventure") =>
         _vm = new(Input.First());
-    }
-    
+
     public override void ProcessInput()
     {
     }
@@ -20,8 +18,5 @@ public sealed class Day21 : Day
         return "";
     }
 
-    public override object Part2()
-    {
-        return "";
-    }
+    public override object Part2() => "";
 }

AOC2019/Day22.cs

@@ -6,13 +6,7 @@ public sealed class Day22() : Day(2019, 22, "Slam Shuffle")
     {
     }
 
-    public override object Part1()
-    {
-        return "";
-    }
+    public override object Part1() => "";
 
-    public override object Part2()
-    {
-        return "";
-    }
+    public override object Part2() => "";
 }

AOC2019/Day24.cs

@@ -6,13 +6,7 @@ public sealed class Day24() : Day(2019, 24, "Planet of Discord")
     {
     }
 
-    public override object Part1()
-    {
-        return "";
-    }
+    public override object Part1() => "";
 
-    public override object Part2()
-    {
-        return "";
-    }
+    public override object Part2() => "";
 }

AOC2019/Day25.cs

@@ -6,13 +6,7 @@ public sealed class Day25() : Day(2019, 25, "Cryostasis")
     {
     }
 
-    public override object Part1()
-    {
-        return "";
-    }
+    public override object Part1() => "";
 
-    public override object Part2()
-    {
-        return "";
-    }
+    public override object Part2() => "";
 }

AOC2020/Day01.cs

@@ -7,10 +7,8 @@ public sealed class Day01() : Day(2020, 1, "Report Repair")
 {
     private ImmutableHashSet<int>? _entries;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _entries = Input.Select(int.Parse).ToImmutableHashSet();
-    }
 
     public override object Part1()
     {
@@ -25,7 +23,7 @@ public sealed class Day01() : Day(2020, 1, "Report Repair")
         foreach (var k in _entries)
             if (i + j + k == 2020)
                 return i * j * k;
-        
+
         return default!;
     }
 }

AOC2020/Day02.cs

@@ -7,10 +7,8 @@ public sealed class Day02() : Day(2020, 2, "Password Philosophy")
 {
     private ImmutableList<Password>? _passwords;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _passwords = Input.Select(p => new Password(p)).ToImmutableList();
-    }
 
     public override object Part1() =>
         _passwords!.Count(p => p.IsValid);

AOC2020/Day03.cs

@@ -7,10 +7,8 @@ public sealed class Day03() : Day(2020, 3, "Toboggan Trajectory")
 {
     private string[]? _grid;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _grid = Input.ToArray();
-    }
 
     private long CountSlope(int dx, int dy)
     {

AOC2020/Day05.cs

@@ -7,14 +7,12 @@ public sealed class Day05() : Day(2020, 5, "Binary Boarding")
 {
     private ImmutableHashSet<int>? _ids;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _ids = Input
             .Select(s =>
                 Convert.ToInt32(s.Replace('F', '0').Replace('B', '1').Replace('L', '0').Replace('R', '1'), 2))
             .OrderBy(i => i)
             .ToImmutableHashSet();
-    }
 
     public override object Part1() => _ids!.Last();
 

AOC2020/Day07.cs

@@ -7,8 +7,7 @@ public sealed class Day07() : Day(2020, 7, "Handy Haversacks")
 {
     private Dictionary<string, IEnumerable<(int Weight, string Name)?>>? _rules;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _rules = Input
             .Select(rule =>
             {
@@ -18,7 +17,6 @@ public sealed class Day07() : Day(2020, 7, "Handy Haversacks")
                 return (outer, inner);
             })
             .ToDictionary(t => t.outer, t => t.inner);
-    }
 
     private static (int, string)? ParseQuantity(string arg)
     {

AOC2020/Day08.cs

@@ -9,10 +9,8 @@ public sealed class Day08() : Day(2020, 8, "Handheld Halting")
     private int _accumulator;
     private int _currentInstruction;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _instructions = Input.Select(ParseLine).ToArray();
-    }
 
     private static (string, int) ParseLine(string line)
     {

AOC2020/Day09.cs

@@ -8,10 +8,8 @@ public sealed class Day09() : Day(2020, 9, "Encoding Error")
     private long[]? _list;
     private long _part1;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _list = Input.Select(long.Parse).ToArray();
-    }
 
     public override object Part1()
     {

AOC2020/Day16.cs

@@ -10,8 +10,8 @@ public sealed class Day16() : Day(2020, 16, "Ticket Translation")
 
     public override void ProcessInput()
     {
-        _tickets = new();
-        _rules = new();
+        _tickets = [];
+        _rules = [];
 
         foreach (var line in Input)
         {

AOC2020/Day17.cs

@@ -5,8 +5,8 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day17() : Day(2020, 17, "Conway Cubes")
 {
-    private readonly Dictionary<(int x, int y, int z), char> _plane = new();
-    private readonly Dictionary<(int x, int y, int z, int w), char> _plane4 = new();
+    private readonly Dictionary<(int x, int y, int z), char> _plane = [];
+    private readonly Dictionary<(int x, int y, int z, int w), char> _plane4 = [];
 
     public override void ProcessInput()
     {
@@ -103,15 +103,9 @@ public sealed class Day17() : Day(2020, 17, "Conway Cubes")
         return next;
     }
 
-    public override object Part1()
-    {
-        var plane = Enumerable.Range(0, 6).Aggregate(_plane, (current, _) => Iterate(current));
-        return plane.Values.Count(v => v == '#');
-    }
+    public override object Part1() =>
+        Enumerable.Range(0, 6).Aggregate(_plane, (current, _) => Iterate(current)).Values.Count(v => v == '#');
 
-    public override object Part2()
-    {
-        var plane = Enumerable.Range(0, 6).Aggregate(_plane4, (current, _) => Iterate4(current));
-        return plane.Values.Count(v => v == '#');
-    }
-}
+    public override object Part2() =>
+        Enumerable.Range(0, 6).Aggregate(_plane4, (current, _) => Iterate4(current)).Values.Count(v => v == '#');
+}

AOC2020/Day18.cs

@@ -7,10 +7,8 @@ public sealed class Day18() : Day(2020, 18, "Operation Order")
 {
     private List<string>? _expressions;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _expressions = Input.Select(line => line.Replace(" ", "")).ToList();
-    }
 
     private static long Calculate(string expr, Func<char, int> precedence)
     {

AOC2020/Day20.cs

@@ -53,29 +53,29 @@ public sealed class Day20() : Day(2020, 20, "Jurassic Jigsaw")
 
         void AddConnection(PuzzlePiece p1, PuzzlePiece p2)
         {
-            if (!connections.ContainsKey(p1)) connections.Add(p1, new());
-            if (!connections.ContainsKey(p2)) connections.Add(p2, new());
+            if (!connections.ContainsKey(p1)) connections.Add(p1, []);
+            if (!connections.ContainsKey(p2)) connections.Add(p2, []);
             connections[p1].Add(p2);
             connections[p2].Add(p1);
         }
 
         foreach (var piece in puzzlePieces)
-        foreach (var (original, flipped) in piece.SidesWithFlippedPaired.Value)
-        {
-            if (sides.TryGetValue(original, out var side))
+            foreach (var (original, flipped) in piece.SidesWithFlippedPaired.Value)
             {
-                AddConnection(piece, side);
+                if (sides.TryGetValue(original, out var side))
+                {
+                    AddConnection(piece, side);
+                }
+                else if (sides.TryGetValue(flipped, out var otherPiece))
+                {
+                    AddConnection(piece, otherPiece);
+                }
+                else
+                {
+                    sides.Add(original, piece);
+                    sides.Add(flipped, piece);
+                }
             }
-            else if (sides.TryGetValue(flipped, out var otherPiece))
-            {
-                AddConnection(piece, otherPiece);
-            }
-            else
-            {
-                sides.Add(original, piece);
-                sides.Add(flipped, piece);
-            }
-        }
 
         return connections;
     }

AOC2020/Day22.cs

@@ -8,10 +8,7 @@ public sealed class Day22() : Day(2020, 22, "Crab Combat")
     private readonly Queue<int> _deck1 = new();
     private readonly Queue<int> _deck2 = new();
 
-    public override void ProcessInput()
-    {
-        Reset();
-    }
+    public override void ProcessInput() => Reset();
 
     private void Reset()
     {

AOC2020/Day23.cs

@@ -5,7 +5,7 @@ namespace AOC2020;
 /// </summary>
 public sealed class Day23() : Day(2020, 23, "Crab Cups")
 {
-    private readonly Dictionary<long, long> _cups = new();
+    private readonly Dictionary<long, long> _cups = [];
     private ImmutableList<long>? _initialCups;
     private long[]? _move;
     private long _current;

AOC2020/Day24.cs

@@ -17,15 +17,12 @@ public sealed class Day24() : Day(2020, 24, "Lobby Layout")
 
     private Dictionary<(int q, int r, int s), Tile>? _tiles;
 
-    public override void ProcessInput()
-    {
-        _tiles = Input
+    public override void ProcessInput() => _tiles = Input
             .Select(Tile.FromLine)
             .GroupBy(t => t.Location)
             .Where(g => g.Count() % 2 == 1)
             .Select(t => t.First())
             .ToDictionary(t => t.Location);
-    }
 
     public override object Part1() => _tiles!.Count;
 

AOC2020/Day25.cs

@@ -9,15 +9,6 @@ public sealed class Day25() : Day(2020, 25, "Combo Breaker")
     {
     }
 
-    public override object Part1()
-    {
-        var cardKey = int.Parse(Input.First());
-        var doorKey = int.Parse(Input.Last());
-        return Transform(doorKey, FindLoopSize(7, cardKey));
-    }
-
-    public override object Part2() => "";
-    
     private static long Transform(long subject, int loopSize)
     {
         var value = 1L;
@@ -40,4 +31,13 @@ public sealed class Day25() : Day(2020, 25, "Combo Breaker")
         }
         return loops;
     }
+
+    public override object Part1()
+    {
+        var cardKey = int.Parse(Input.First());
+        var doorKey = int.Parse(Input.Last());
+        return Transform(doorKey, FindLoopSize(7, cardKey));
+    }
+
+    public override object Part2() => "";
 }

AOC2021/Day01.cs

@@ -7,10 +7,8 @@ public sealed class Day01() : Day(2021, 1, "Sonar Sweep")
 {
     private List<int>? _readings;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _readings = Input.Select(int.Parse).ToList();
-    }
 
     public override object Part1() =>
         Enumerable.Range(0, _readings!.Count - 1).Count(i => _readings[i + 1] > _readings[i]);

AOC2021/Day03.cs

@@ -7,17 +7,15 @@ public sealed class Day03() : Day(2021, 3, "Binary Diagnostic")
 {
     private List<string>? _report;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _report = Input.ToList();
-    }
 
     public override object Part1()
     {
         var l = _report!.Count / 2;
         var g = new StringBuilder();
         var e = new StringBuilder();
-        
+
         foreach (var i in Enumerable.Range(0, _report[0].Length))
         {
             var ones = _report.Select(r => r[i]).Count(c => c == '1');
@@ -25,7 +23,7 @@ public sealed class Day03() : Day(2021, 3, "Binary Diagnostic")
             e.Append(ones > l ? '0' : '1');
         }
 
-        var gamma   = g.ToString().BigIntegerFromBinaryString();
+        var gamma = g.ToString().BigIntegerFromBinaryString();
         var epsilon = e.ToString().BigIntegerFromBinaryString();
 
         return gamma * epsilon;
@@ -38,7 +36,7 @@ public sealed class Day03() : Day(2021, 3, "Binary Diagnostic")
 
         char MostCommon(int i, IReadOnlyCollection<string> report) =>
             report.Count(r => r[i] == '1') >= report.Count / 2.0 ? '1' : '0';
-        
+
         var i = 0;
         while (o.Count > 1)
         {

AOC2021/Day04.cs

@@ -12,15 +12,15 @@ public sealed class Day04() : Day(2021, 4, "Giant Squid")
     public override void ProcessInput()
     {
         _call = Input.First().Split(',').Select(int.Parse).ToList();
-        _boards = new();
+        _boards = [];
 
-        List<int> currentBoard = new();
+        List<int> currentBoard = [];
         foreach (var line in Input.Skip(2))
         {
             if (string.IsNullOrWhiteSpace(line))
             {
                 _boards.Add(currentBoard);
-                currentBoard = new();
+                currentBoard = [];
                 continue;
             }
 
@@ -47,7 +47,7 @@ public sealed class Day04() : Day(2021, 4, "Giant Squid")
 
     public override object Part2()
     {
-        Dictionary<int, bool> wonBoards = new();
+        Dictionary<int, bool> wonBoards = [];
         for (var i = 0; i < _boards!.Count; i++)
             wonBoards[i] = false;
 

AOC2021/Day06.cs

@@ -10,11 +10,11 @@ public sealed class Day06() : Day(2021, 6, "Lanternfish")
     public override void ProcessInput()
     {
         var fishes = Input.First().Split(',').Select(long.Parse).ToList();
-        Dictionary<long, long> counts = new();
-        
+        Dictionary<long, long> counts = [];
+
         for (var i = 0; i <= 8; i++)
             counts[i] = fishes.Count(x => x == i);
-        
+
         for (var i = 0; i < 256; i++)
         {
             var breeders = counts[0];

AOC2021/Day07.cs

@@ -7,10 +7,8 @@ public sealed class Day07() : Day(2021, 7, "The Treachery of Whales")
 {
     private List<long>? _tape;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _tape = Input.First().Split(',').Select(long.Parse).OrderBy(i => i).ToList();
-    }
 
     private static long ArithmeticSumTo(long n) => n * (n + 1) / 2L;
 
@@ -24,7 +22,7 @@ public sealed class Day07() : Day(2021, 7, "The Treachery of Whales")
     {
         var avg = (decimal)_tape!.Sum() / _tape!.Count;
         var floor = _tape.Select(t => ArithmeticSumTo(Math.Abs(t - (long)Math.Floor(avg)))).Sum();
-        var ceil  = _tape.Select(t => ArithmeticSumTo(Math.Abs(t - (long)Math.Ceiling(avg)))).Sum();
+        var ceil = _tape.Select(t => ArithmeticSumTo(Math.Abs(t - (long)Math.Ceiling(avg)))).Sum();
         return Math.Min(floor, ceil);
     }
 }

AOC2021/Day08.cs

@@ -42,7 +42,7 @@ public sealed class Day08() : Day(2021, 8, "Seven Segment Search")
                 lit = "0000000".ToCharArray();
                 foreach (var c in signal)
                     lit[Array.IndexOf(PossibleMappings[i], c)] = '1';
-                
+
                 var match = MatchDigit(new(lit));
                 if (match == -1)
                 {
@@ -68,7 +68,7 @@ public sealed class Day08() : Day(2021, 8, "Seven Segment Search")
             lit = "0000000".ToCharArray();
             foreach (var c in o)
                 lit[Array.IndexOf(PossibleMappings[i], c)] = '1';
-            
+
             digits.Append(MatchDigit(new(lit)));
         }
 

AOC2021/Day09.cs

@@ -14,21 +14,21 @@ public sealed class Day09() : Day(2021, 9, "Smoke Basin")
     public override void ProcessInput()
     {
         _part1Sum = 0;
-        _lowPoints = new();
+        _lowPoints = [];
         _map = Input.ToList();
 
         for (var y = 0; y < _map.Count; y++)
-        for (var x = 0; x < _map[y].Length; x++)
-        {
-            var c = _map[y][x];
-            if (y > 0 && _map[y - 1][x] <= c) continue;
-            if (y < _map.Count - 1 && _map[y + 1][x] <= c) continue;
-            if (x > 0 && _map[y][x - 1] <= c) continue;
-            if (x < _map[y].Length - 1 && _map[y][x + 1] <= c) continue;
+            for (var x = 0; x < _map[y].Length; x++)
+            {
+                var c = _map[y][x];
+                if (y > 0 && _map[y - 1][x] <= c) continue;
+                if (y < _map.Count - 1 && _map[y + 1][x] <= c) continue;
+                if (x > 0 && _map[y][x - 1] <= c) continue;
+                if (x < _map[y].Length - 1 && _map[y][x + 1] <= c) continue;
 
-            _lowPoints.Add((x, y));
-            _part1Sum += c - '0' + 1;
-        }
+                _lowPoints.Add((x, y));
+                _part1Sum += c - '0' + 1;
+            }
     }
 
     public override object Part1() => _part1Sum;

AOC2021/Day10.cs

@@ -29,7 +29,7 @@ public sealed class Day10() : Day(2021, 10, "Syntax Scoring")
         { '<', 4 }
     };
 
-    private readonly List<long> _scores2 = new();
+    private readonly List<long> _scores2 = [];
 
     private long _score1;
 

AOC2021/Day11.cs

@@ -15,12 +15,12 @@ public sealed class Day11() : Day(2021, 11, "Dumbo Octopus")
         while (true)
         {
             _totalTurns++;
-            
+
             // increment all octopuses
             for (var row = 0; row < _octopusField.Length; row++)
             for (var col = 0; col < _octopusField[row].Length; col++)
                 _octopusField[row][col]++;
-            
+
             // flash any that exceeded 10
             for (var row = 0; row < _octopusField.Length; row++)
             for (var col = 0; col < _octopusField[row].Length; col++)
@@ -34,7 +34,7 @@ public sealed class Day11() : Day(2021, 11, "Dumbo Octopus")
                     _octopusField[row][col] = 0;
                 else
                     done = false;
-            
+
             if (_totalTurns == 100) _flashesAfter100 = _flashTally;
             if (done) break;
         }

AOC2021/Day12.cs

@@ -5,7 +5,7 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day12() : Day(2021, 12, "Passage Pathing")
 {
-    private readonly Dictionary<string, List<string>> _edges = new();
+    private readonly Dictionary<string, List<string>> _edges = [];
 
     public override void ProcessInput()
     {
@@ -14,10 +14,10 @@ public sealed class Day12() : Day(2021, 12, "Passage Pathing")
             var s = line.Split('-', 2);
 
             if (_edges.ContainsKey(s[0])) _edges[s[0]].Add(s[1]);
-            else _edges[s[0]] = new() { s[1] };
+            else _edges[s[0]] = [s[1]];
 
             if (_edges.ContainsKey(s[1])) _edges[s[1]].Add(s[0]);
-            else _edges[s[1]] = new() { s[0] };
+            else _edges[s[1]] = [s[0]];
         }
     }
 
@@ -49,14 +49,14 @@ public sealed class Day12() : Day(2021, 12, "Passage Pathing")
             return true;
         if (seen.GetValueOrDefault("_twice", false))
             return false;
-        
+
         seen["_twice"] = true;
         return true;
     }
 
     public override object Part1() =>
-        WalkGraph(_edges, "start", new());
+        WalkGraph(_edges, "start", []);
 
     public override object Part2() =>
-        TraverseGraph(_edges, "start", new());
+        TraverseGraph(_edges, "start", []);
 }

AOC2021/Day13.cs

@@ -13,24 +13,24 @@ public sealed class Day13() : Day(2021, 13, "Transparent Origami")
     public override void ProcessInput()
     {
         var s = Input.Split("").ToList();
-        
+
         _dots = s[0].Select(p =>
         {
             var i = p.Split(',', 2).Select(int.Parse).ToList();
             return (i[0], i[1]);
         }).ToList();
-        
+
         _folds = s[1].Select(p => p.Split(' ').Skip(2).First()).Select(p =>
         {
             var i = p.Split('=', 2);
             return (i[0][0], int.Parse(i[1]));
         }).ToList();
     }
-    
+
     private static List<(int x, int y)> DoFold(List<(int x, int y)> grid, char axis, int at)
     {
-        List<(int, int)> result = new();
-        
+        List<(int, int)> result = [];
+
         switch (axis)
         {
             case 'x':

AOC2021/Day16.cs

@@ -34,7 +34,7 @@ public sealed class Day16() : Day(2021, 16, "Packet Decoder")
                     if (chunk[0] == '0') break;
                 }
 
-                return (new(version, typeId, Convert.ToInt64(literalBits.ToString(), 2), new()), index);
+                return (new(version, typeId, Convert.ToInt64(literalBits.ToString(), 2), []), index);
             }
 
             switch (input[index++])

AOC2021/Day17.cs

@@ -7,8 +7,7 @@ public sealed class Day17() : Day(2021, 17, "Trick Shot")
 {
     private List<int>? _target;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _target = Input.First()
             .Split(' ', StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries)
             .Skip(2)
@@ -16,7 +15,6 @@ public sealed class Day17() : Day(2021, 17, "Trick Shot")
             .Select(i => i.TrimEnd(','))
             .Select(int.Parse)
             .ToList();
-    }
 
     public override object Part1()
     {

AOC2021/Day18.cs

@@ -7,13 +7,13 @@ public sealed class Day18() : Day(2021, 18, "Snailfish")
 {
     private List<string>? _fishes;
 
-    public override void ProcessInput()
-    {
-        _fishes = Input.ToList();
-    }
+    public override void ProcessInput() => _fishes = Input.ToList();
 
     private static Tree<int> Parse(string input)
     {
+        var cursor = 0;
+        return new(ParseFish(null, input, ref cursor));
+
         static Tree<int>.Node ParseFish(Tree<int>.Node? parent, string input, ref int cursor)
         {
             if (input[cursor] != '[') return new(parent, input[cursor++] - '0');
@@ -26,14 +26,11 @@ public sealed class Day18() : Day(2021, 18, "Snailfish")
             cursor++;
             return node;
         }
-
-        var cursor = 0;
-        return new(ParseFish(null, input, ref cursor));
     }
 
     private static Tree<int> Add(Tree<int> a, Tree<int> b)
     {
-        var reduced = new Tree<int>(new(null, -1) {Left = a.Root, Right = b.Root});
+        var reduced = new Tree<int>(new(null, -1) { Left = a.Root, Right = b.Root });
         Reduce(reduced);
         return reduced;
     }
@@ -60,13 +57,16 @@ public sealed class Day18() : Day(2021, 18, "Snailfish")
 
     private static void Reduce(Tree<int> tree)
     {
-        bool ReduceRecurse(Tree<int>.Node node, Func<Tree<int>, Tree<int>.Node, bool> reducer)
+        var changed = true;
+        while (changed)
         {
-            if (reducer(tree, node)) return true;
-            if (node.Left != null && ReduceRecurse(node.Left, reducer)) return true;
-            return node.Right != null && ReduceRecurse(node.Right, reducer);
+            changed = false;
+            while (ReduceRecurse(tree.Root, Explode)) changed = true;
+            if (ReduceRecurse(tree.Root, Split)) changed = true;
         }
 
+        return;
+
         bool Explode(Tree<int> t, Tree<int>.Node node)
         {
             if (node.Data != -1 || node.DistanceToParent(t.Root) < 4) return false;
@@ -90,12 +90,11 @@ public sealed class Day18() : Day(2021, 18, "Snailfish")
             return true;
         }
 
-        var changed = true;
-        while (changed)
+        bool ReduceRecurse(Tree<int>.Node node, Func<Tree<int>, Tree<int>.Node, bool> reducer)
         {
-            changed = false;
-            while (ReduceRecurse(tree.Root, Explode)) changed = true;
-            if (ReduceRecurse(tree.Root, Split)) changed = true;
+            if (reducer(tree, node)) return true;
+            if (node.Left != null && ReduceRecurse(node.Left, reducer)) return true;
+            return node.Right != null && ReduceRecurse(node.Right, reducer);
         }
     }
 

AOC2021/Day19.cs

@@ -9,10 +9,9 @@ public sealed class Day19() : Day(2021, 19, "Beacon Scanner")
         { (0, 1, 0), (0, -1, 0), (1, 0, 0), (-1, 0, 0), (0, 0, 1), (0, 0, -1) };
 
     private List<HashSet<Vector3>>? _scans;
-    private List<HashSet<Vector3>> _scanners = new();
+    private List<HashSet<Vector3>> _scanners = [];
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _scans = Input
             .Aggregate(new List<HashSet<Vector3>>(), (list, line) =>
             {
@@ -20,7 +19,7 @@ public sealed class Day19() : Day(2021, 19, "Beacon Scanner")
 
                 if (line.StartsWith("---"))
                 {
-                    list.Add(new());
+                    list.Add([]);
                     return list;
                 }
 
@@ -28,7 +27,6 @@ public sealed class Day19() : Day(2021, 19, "Beacon Scanner")
                 list[^1].Add((parts[0], parts[1], parts[2]));
                 return list;
             });
-    }
 
     private static Vector3 Transform(Vector3 pt, Vector3 up, int rotation)
     {

AOC2021/Day21.cs

@@ -6,7 +6,7 @@ namespace AOC2021;
 public sealed class Day21() : Day(2021, 21, "Dirac Dice")
 {
     private int _player1, _player2;
-    private readonly Dictionary<int, ulong> _possibleRollOutComes = new();
+    private readonly Dictionary<int, ulong> _possibleRollOutComes = [];
     private int _deterministicDie = 1;
     private int _rollCount;
     private ulong _player1Victories, _player2Victories;

AOC2021/Day22.cs

@@ -5,7 +5,7 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day22() : Day(2021, 22, "Reactor Reboot")
 {
-    private readonly List<Instruction> _instructions = new();
+    private readonly List<Instruction> _instructions = [];
 
     public override void ProcessInput()
     {
@@ -18,7 +18,7 @@ public sealed class Day22() : Day(2021, 22, "Reactor Reboot")
                 .SelectMany(l => l.Split(".."))
                 .Select(int.Parse)
                 .ToList();
-            
+
             _instructions.Add(new(s[0] == "off", new(new(e[0], e[1]), new(e[2], e[3]), new(e[4], e[5]))));
         }
     }
@@ -26,7 +26,7 @@ public sealed class Day22() : Day(2021, 22, "Reactor Reboot")
     private long ActiveCubes(int x, Region3D region)
     {
         if (region.IsEmpty || x < 0) return 0;
-        
+
         var intersection = region.Intersect(_instructions[x].Region);
         var activeInRegion = ActiveCubes(x - 1, region);
         var activeInIntersection = ActiveCubes(x - 1, intersection);
@@ -34,7 +34,7 @@ public sealed class Day22() : Day(2021, 22, "Reactor Reboot")
 
         // outside the intersection is unaffected, the rest is either on or off:
         return _instructions[x].Disable ? activeOutsideIntersection : activeOutsideIntersection + intersection.Volume;
-    
+
     }
 
     public override object Part1()

AOC2021/Day23.cs

@@ -7,10 +7,8 @@ public sealed class Day23() : Day(2021, 23, "Amphipod")
 {
     private List<char>? _crabs;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _crabs = Input.SelectMany(l => l).Where(char.IsLetter).ToList();
-    }
 
     private static IEnumerable<int> BreadthFirstSearch(string s, int i)
     {
@@ -32,53 +30,50 @@ public sealed class Day23() : Day(2021, 23, "Amphipod")
         }
     }
 
-    private static Dijkstra<State, (State state, int distance)> GetPathFinder(int size)
+    private static Dijkstra<State, (State state, int distance)> GetPathFinder(int size) => new()
     {
-        return new()
+        Neighbors = state =>
         {
-            Neighbors = state =>
+            // Find all neighbors from the current state
+            var possible = new List<(State, int)>();
+            var entries = new[] { 2, 4, 6, 8 };
+            // Add each way of taking an item out of a hole into the hallway
+            foreach (var i in entries)
             {
-                // Find all neighbors from the current state
-                var possible = new List<(State, int)>();
-                var entries = new[] { 2, 4, 6, 8 };
-                // Add each way of taking an item out of a hole into the hallway
-                foreach (var i in entries)
+                var hole = state[i / 2 - 1];
+                if (string.IsNullOrWhiteSpace(hole)) continue;
+                var targets = BreadthFirstSearch(state.Hallway, i).Except(entries).ToList();
+                foreach (var target in targets)
                 {
-                    var hole = state[i / 2 - 1];
-                    if (string.IsNullOrWhiteSpace(hole)) continue;
-                    var targets = BreadthFirstSearch(state.Hallway, i).Except(entries).ToList();
-                    foreach (var target in targets)
-                    {
-                        var data = state.Hallway.ToCharArray();
-                        data[target] = hole.Trim()[0];
-                        var newHole = hole.Trim()[1..].PadLeft(size);
-                        var next = State.New(state, data, i / 2 - 1, newHole);
-                        var cost = Math.Abs(target - i) + (size - newHole.Trim().Length);
-                        cost *= 10.Pow(data[target] - 'A');
-                        possible.Add((next, cost));
-                    }
-                }
-
-                foreach (var (at, which) in state.Hallway.Indexed().WhereValue(char.IsLetter))
-                {
-                    var dest = which - 'A';
-                    if (!BreadthFirstSearch(state.Hallway, at).Intersect(entries).Select(i => i / 2 - 1)
-                            .Contains(dest)) continue;
-                    if (state[dest]!.Trim().Any(c => c != which)) continue;
                     var data = state.Hallway.ToCharArray();
-                    data[at] = ' ';
-                    var next = State.New(state, data, dest, (which + state[dest]!.Trim()).PadLeft(size));
-                    var cost = Math.Abs(at - (dest + 1) * 2) + (size - state[dest]!.Trim().Length);
-                    cost *= 10.Pow(dest);
+                    data[target] = hole.Trim()[0];
+                    var newHole = hole.Trim()[1..].PadLeft(size);
+                    var next = State.New(state, data, i / 2 - 1, newHole);
+                    var cost = Math.Abs(target - i) + (size - newHole.Trim().Length);
+                    cost *= 10.Pow(data[target] - 'A');
                     possible.Add((next, cost));
                 }
+            }
 
-                return possible;
-            },
-            Distance = tuple => tuple.distance,
-            Cell = (_, tuple) => tuple.state
-        };
-    }
+            foreach (var (at, which) in state.Hallway.Indexed().WhereValue(char.IsLetter))
+            {
+                var dest = which - 'A';
+                if (!BreadthFirstSearch(state.Hallway, at).Intersect(entries).Select(i => i / 2 - 1)
+                        .Contains(dest)) continue;
+                if (state[dest]!.Trim().Any(c => c != which)) continue;
+                var data = state.Hallway.ToCharArray();
+                data[at] = ' ';
+                var next = State.New(state, data, dest, (which + state[dest]!.Trim()).PadLeft(size));
+                var cost = Math.Abs(at - (dest + 1) * 2) + (size - state[dest]!.Trim().Length);
+                cost *= 10.Pow(dest);
+                possible.Add((next, cost));
+            }
+
+            return possible;
+        },
+        Distance = tuple => tuple.distance,
+        Cell = (_, tuple) => tuple.state
+    };
 
     public override object Part1()
     {

AOC2021/Day24.cs

@@ -5,7 +5,7 @@ namespace AOC2021;
 /// </summary>
 public sealed class Day24() : Day(2021, 24, "Arithmetic Logic Unit")
 {
-    private readonly Dictionary<int, (int x, int y)> _keys = new();
+    private readonly Dictionary<int, (int x, int y)> _keys = [];
 
     public override void ProcessInput()
     {

AOC2021/Day25.cs

@@ -7,10 +7,8 @@ public sealed class Day25() : Day(2021, 25, "Sea Cucumber")
 {
     private char[][]? _cucumbers;
 
-    public override void ProcessInput()
-    {
+    public override void ProcessInput() =>
         _cucumbers = Input.Select(l => l.ToCharArray()).ToArray();
-    }
 
     private static char[][]? DoStep(IReadOnlyList<char[]> arr)
     {
@@ -38,15 +36,15 @@ public sealed class Day25() : Day(2021, 25, "Sea Cucumber")
             result2[i] = new char[w];
 
         for (var i = 0; i < h; i++)
-        for (var j = 0; j < w; j++)
-        {
-            if (result2[i][j] == 0) result2[i][j] = result[i][j];
-            if (result[i][j] != 'v') continue;
-            if (result[(i + 1) % h][j] != '.') continue;
-            result2[i][j] = '.';
-            result2[(i + 1) % h][j] = 'v';
-            moved = true;
-        }
+            for (var j = 0; j < w; j++)
+            {
+                if (result2[i][j] == 0) result2[i][j] = result[i][j];
+                if (result[i][j] != 'v') continue;
+                if (result[(i + 1) % h][j] != '.') continue;
+                result2[i][j] = '.';
+                result2[(i + 1) % h][j] = 'v';
+                moved = true;
+            }
 
         return moved ? result2 : null;
     }

AOC2022/Day07.cs

@@ -5,7 +5,7 @@ namespace AOC2022;
 /// </summary>
 public sealed class Day07() : Day(2022, 7, "No Space Left On Device")
 {
-    private readonly DefaultDictionary<string, long> _dirs = new();
+    private readonly DefaultDictionary<string, long> _dirs = [];
 
     public override void ProcessInput()
     {
@@ -23,7 +23,7 @@ public sealed class Day07() : Day(2022, 7, "No Space Left On Device")
             else
             {
                 if (!long.TryParse(line.Split(' ')[0], out var filesize)) continue;
-                
+
                 var pathList = path.ToList();
                 pathList.Reverse();
 

AOC2022/Day08.cs

@@ -67,12 +67,12 @@ public sealed class Day08() : Day(2022, 8, "Treetop Tree House")
     {
         var max = 0;
         for (var y = 0; y < _trees!.Length; y++)
-        for (var x = 0; x < _trees[0].Length; x++)
-        {
-            var (_, score) = ScoreCoord(x, y);
-            if (score > max) max = score;
-        }
+            for (var x = 0; x < _trees[0].Length; x++)
+            {
+                var (_, score) = ScoreCoord(x, y);
+                if (score > max) max = score;
+            }
 
         return max;
     }
-}
+}

AOC2022/Day09.cs

@@ -24,7 +24,7 @@ public sealed class Day09() : Day(2022, 9, "Rope Bridge")
                 case 'L': rope[0].x--; break;
                 case 'R': rope[0].x++; break;
             }
-                
+
             foreach (var i in Enumerable.Range(1, ropeLength - 1))
             {
                 int dx = rope[i - 1].x - rope[i].x, dy = rope[i - 1].y - rope[i].y;

AOC2022/Day10.cs

@@ -5,17 +5,17 @@ namespace AOC2022;
 /// </summary>
 public sealed class Day10() : Day(2022, 10, "Cathode-Ray Tube")
 {
-    private readonly List<int> _interestingSignals = new();
+    private readonly List<int> _interestingSignals = [];
     private readonly List<char> _charMap = Enumerable.Range(0, 6 * 40).Select(_ => ' ').ToList();
 
     public override void ProcessInput()
     {
         int x = 1, cycle = 1;
         foreach (var line in Input)
-        {               
+        {
             CpuTick(ref cycle, x);
             if (!line.StartsWith("addx")) continue;
-            
+
             CpuTick(ref cycle, x);
             x += int.Parse(line.Split(' ')[1]);
         }

AOC2022/Day11.cs

@@ -26,7 +26,7 @@ public sealed class Day11() : Day(2022, 11, "Monkey in the Middle")
                 item = monkey.Operation(item);
                 if (part1) item /= 3;
                 item %= _lcm;
-                
+
                 monkey.InspectionCount++;
                 var dest = item % monkey.ModTest == 0 ? monkey.TrueDest : monkey.FalseDest;
                 _monkeys[dest].Items.Enqueue(item);
@@ -90,4 +90,4 @@ public sealed class Day11() : Day(2022, 11, "Monkey in the Middle")
             return m;
         }
     }
-}
+}

AOC2022/Day12.cs

@@ -5,8 +5,8 @@ namespace AOC2022;
 /// </summary>
 public sealed class Day12() : Day(2022, 12, "Hill Climbing Algorithm")
 {
-    private readonly Dictionary<(int x, int y), int> _grid = new();
-    private static readonly List<(int x, int y)> Directions = new() { (-1, 0), (1, 0), (0, -1), (0, 1) };
+    private readonly Dictionary<(int x, int y), int> _grid = [];
+    private static readonly List<(int x, int y)> Directions = [(-1, 0), (1, 0), (0, -1), (0, 1)];
     private (int x, int y) _startCoord, _destCoord;
 
     public override void ProcessInput()
@@ -53,4 +53,4 @@ public sealed class Day12() : Day(2022, 12, "Hill Climbing Algorithm")
 
     public override object Part1() => ShortestDistance(_destCoord, _startCoord);
     public override object Part2() => ShortestDistance(_destCoord, null, 0);
-}
+}

AOC2022/Day14.cs

@@ -17,7 +17,7 @@ public sealed class Day14() : Day(2022, 14, "Regolith Reservoir")
 
     private static HashSet<(int x, int y)> PourSand((int x, int y) start, int bottom, Func<(int x, int y), bool> wall)
     {
-        HashSet<(int x, int y)> sand = new();
+        HashSet<(int x, int y)> sand = [];
 
         while (true)
         {
@@ -77,4 +77,4 @@ public sealed class Day14() : Day(2022, 14, "Regolith Reservoir")
 
     public override object Part2() =>
         PourSand(_start, int.MaxValue, p => p.y == _bottom + 2 || _walls!.Contains(p)).Count;
-}
+}

AOC2022/Day15.cs

@@ -9,13 +9,7 @@ public sealed class Day15() : Day(2022, 15, "Beacon Exclusion Zone")
     {
     }
 
-    public override object Part1()
-    {
-        return "";
-    }
+    public override object Part1() => "";
 
-    public override object Part2()
-    {
-        return "";
-    }
+    public override object Part2() => "";
 }

AOC2022/Day16.cs

@@ -9,13 +9,7 @@ public sealed class Day16() : Day(2022, 16, "Proboscidea Volcanium")
     {
     }
 
-    public override object Part1()
-    {
-        return "";
-    }
+    public override object Part1() => "";
 
-    public override object Part2()
-    {
-        return "";
-    }
+    public override object Part2() => "";
 }

AOC2022/Day17.cs

@@ -9,13 +9,7 @@ public sealed class Day17() : Day(2022, 17, "Pyroclastic Flow")
     {
     }
 
-    public override object Part1()
-    {
-        return "";
-    }
+    public override object Part1() => "";
 
-    public override object Part2()
-    {
-        return "";
-    }
+    public override object Part2() => "";
 }