Add utils to parse 2D array

Author: Peter554

2024/ruby/.rubocop.yml

@@ -16,3 +16,9 @@ Style/Documentation:
 
 Style/MultilineBlockChain:
   Enabled: false
+
+Naming/MethodParameterName:
+  Enabled: false
+
+Minitest/MultipleAssertions:
+  Enabled: false

2024/ruby/lib/util.rb

@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+module Util
+  Point2D = Data.define(:x, :y)
+
+  class Array2D
+    def initialize(n_rows, n_cols)
+      @n_rows = n_rows
+      @n_cols = n_cols
+      @data = Array.new(n_rows * n_cols)
+    end
+
+    def [](p)
+      if p.instance_of? Point2D
+        row_idx = p.y
+        col_idx = p.x
+      else
+        row_idx, col_idx = p
+      end
+
+      raise IndexError if row_idx.negative? || row_idx >= @n_rows || col_idx.negative? || col_idx >= @n_cols
+
+      @data[(row_idx * @n_cols) + col_idx]
+    end
+
+    def []=(p, value)
+      if p.instance_of? Point2D
+        row_idx = p.y
+        col_idx = p.x
+      else
+        row_idx, col_idx = p
+      end
+
+      raise IndexError if row_idx.negative? || row_idx >= @n_rows || col_idx.negative? || col_idx >= @n_cols
+
+      @data[(row_idx * @n_cols) + col_idx] = value
+    end
+
+    def self.parse(s)
+      a = Array2D.new(
+        s.split.length,
+        s.split[0].length
+      )
+      s.split.each_with_index do |row, row_idx|
+        row.chars.each_with_index do |char, col_idx|
+          a[[row_idx, col_idx]] = char
+        end
+      end
+      a
+    end
+  end
+end

2024/ruby/test/util_test.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require 'minitest/autorun'
+require_relative '../lib/util'
+
+module UtilTest
+  class Array2DTest < Minitest::Test
+    def test_parse
+      s = "ABC
+DEF"
+
+      a = Util::Array2D.parse(s)
+
+      assert_equal 'A', a[[0, 0]]
+      assert_equal 'B', a[[0, 1]]
+      assert_equal 'C', a[[0, 2]]
+      assert_equal 'D', a[[1, 0]]
+      assert_equal 'E', a[[1, 1]]
+      assert_equal 'F', a[[1, 2]]
+    end
+  end
+end