変なカレンダー生成プログラムの作成（レベル3）

.devcontainer/devcontainer.json

@@ -0,0 +1,22 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/ruby
+{
+	"name": "Ruby",
+	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
+	"image": "ruby:3.3.5-bullseye"
+
+	// Features to add to the dev container. More info: https://containers.dev/features.
+	// "features": {},
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	// "postCreateCommand": "ruby --version",
+
+	// Configure tool-specific properties.
+	// "customizations": {},
+
+	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+	// "remoteUser": "root"
+}

lib/sg_strange_calendar.rb

@@ -1,9 +1,70 @@
+require 'date'
+
 class SgStrangeCalendar
   def initialize(year, today = nil)
-    # write your code here
+    @year = year
+    @today = today
   end
 
   def generate(vertical: false)
-    # write your code here
+    builder = vertical ? VerticalBuilder : HorizontalBuilder
+    builder.new(@year, @today).build
+  end
+
+  class Builder
+    WDAYS = %w[Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo].freeze
+    MONTHS = %w[Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec].freeze
+    BLANK = ' '.freeze
+
+    private_constant :WDAYS, :MONTHS, :BLANK
+
+    def initialize(year, today)
+      @year = year
+      @today = today
+    end
+
+    def build
+      calendar = rows.map.with_index do |line, i|
+        [ths[i].ljust(4), *line].join(' ').gsub(/\s(\[\d+\])(?:\s|\z)/) { $1 }.rstrip
+      end
+      [header.join(' '), *calendar].join("\n")
+    end
+
+    private
+
+    def days_in(month)
+      begining_of_month, end_of_month = Date.new(@year, month, 1), Date.new(@year, month, -1)
+      array = [*begining_of_month..end_of_month].map do |date|
+        date == @today ? "[#{date.day}]".rjust(length + 2) : date.day.to_s.rjust(length)
+      end
+      forward_blanks = Array.new(begining_of_month.wday, BLANK.rjust(length))
+      array.unshift(*forward_blanks)
+      array.fill(BLANK.rjust(length), array.size...WDAYS.size)
+    end
+
+    def header = raise NotImplementedError
+    def ths = raise NotImplementedError
+    def length = raise NotImplementedError
+    def rows = raise NotImplementedError
+  end
+
+  class HorizontalBuilder < Builder
+    private
+
+    def header = @header ||= [@year.to_s, *WDAYS.dup]
+    def ths = @ths ||= MONTHS.dup
+    def length = 2
+    def rows = @rows ||= [*1..12].map(&method(:days_in))
   end
+
+  class VerticalBuilder < Builder
+    private
+
+    def header = @header ||= [@year.to_s, *MONTHS.dup]
+    def ths = @ths ||= WDAYS.dup
+    def length = 3
+    def rows = @rows ||= [*1..12].map(&method(:days_in)).transpose
+  end
+
+  private_constant :Builder, :HorizontalBuilder, :VerticalBuilder
 end

test/sg_strange_calendar_test.rb

@@ -44,7 +44,6 @@ def test_level_1_for_2025
   end
 
   def test_level_2_for_2024_01_01
-    skip "レベル2にチャレンジする人はこの行を削除してください"
     expected = <<~TXT.chomp
       2024 Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo
       Jan     [1] 2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
@@ -66,7 +65,6 @@ def test_level_2_for_2024_01_01
   end
 
   def test_level_2_for_2024_12_09
-    skip "レベル2にチャレンジする人はこの行を削除してください"
     expected = <<~TXT.chomp
       2024 Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo
       Jan      1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
@@ -88,7 +86,6 @@ def test_level_2_for_2024_12_09
   end
 
   def test_level_2_for_2025_03_31
-    skip "レベル2にチャレンジする人はこの行を削除してください"
     expected = <<~TXT.chomp
       2025 Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo
       Jan            1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
@@ -110,7 +107,6 @@ def test_level_2_for_2025_03_31
   end
 
   def test_level_2_all
-    skip "レベル2にチャレンジする人はこの行を削除してください"
     file_path = File.expand_path('level2.txt', File.dirname(__FILE__))
     calendars = File.read(file_path).lines.each_slice(13).map(&:join).map(&:chomp)
     from_date = Date.new(2025, 1, 1)
@@ -123,7 +119,6 @@ def test_level_2_all
   end
 
   def test_level_3_for_2024
-    skip "レベル2およびレベル3にチャレンジする人はこの行を削除してください"
     expected = <<~TXT.chomp
       2024 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
       Su                                     1           1
@@ -169,7 +164,6 @@ def test_level_3_for_2024
   end
 
   def test_level_3_for_2024_01_01
-    skip "レベル2およびレベル3にチャレンジする人はこの行を削除してください"
     expected = <<~TXT.chomp
       2024 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
       Su                                     1           1
@@ -216,7 +210,6 @@ def test_level_3_for_2024_01_01
   end
 
   def test_level_3_for_2024_12_09
-    skip "レベル2およびレベル3にチャレンジする人はこの行を削除してください"
     expected = <<~TXT.chomp
       2024 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
       Su                                     1           1
@@ -263,7 +256,6 @@ def test_level_3_for_2024_12_09
   end
 
   def test_level_3_for_2025_03_31
-    skip "レベル2およびレベル3にチャレンジする人はこの行を削除してください"
     expected = <<~TXT.chomp
       2025 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
       Su                         1
@@ -310,7 +302,6 @@ def test_level_3_for_2025_03_31
   end
 
   def test_level_3_all
-    skip "レベル2およびレベル3にチャレンジする人はこの行を削除してください"
     file_path = File.expand_path('level3.txt', File.dirname(__FILE__))
     calendars = File.read(file_path).lines.each_slice(38).map(&:join).map(&:chomp)
     from_date = Date.new(2025, 1, 1)