2025-03-12 v. 8.9.2: added "2007. Find Original Array From Doubled Array"

Author: fartem

README.md

@@ -725,6 +725,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 1910. Remove All Occurrences of a Substring                                         | [Link](https://leetcode.com/problems/remove-all-occurrences-of-a-substring/)                                         | [Link](./lib/medium/1910_remove_all_occurrences_of_a_substring.rb)                                         | [Link](./test/medium/test_1910_remove_all_occurrences_of_a_substring.rb)                                         |
 | 1985. Find the Kth Largest Integer in the Array                                     | [Link](https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array/)                                     | [Link](./lib/medium/1985_find_the_kth_largest_integer_in_the_array.rb)                                     | [Link](./test/medium/test_1985_find_the_kth_largest_integer_in_the_array.rb)                                     |
 | 1996. The Number of Weak Characters in the Game                                     | [Link](https://leetcode.com/problems/the-number-of-weak-characters-in-the-game/)                                     | [Link](./lib/medium/1996_the_number_of_weak_characters_in_the_game.rb)                                     | [Link](./test/medium/test_1996_the_number_of_weak_characters_in_the_game.rb)                                     |
+| 2007. Find Original Array From Doubled Array                                        | [Link](https://leetcode.com/problems/find-original-array-from-doubled-array/)                                        | [Link](./lib/medium/2007_find_original_array_from_doubled_array.rb)                                        | [Link](./test/medium/test_2007_find_original_array_from_doubled_array.rb)                                        |
 | 2116. Check if a Parentheses String Can Be Valid                                    | [Link](https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid/)                                    | [Link](./lib/medium/2116_check_if_a_parentheses_string_can_be_valid.rb)                                    | [Link](./test/medium/test_2116_check_if_a_parentheses_string_can_be_valid.rb)                                    |
 | 2425. Bitwise XOR of All Pairings                                                   | [Link](https://leetcode.com/problems/bitwise-xor-of-all-pairings/)                                                   | [Link](./lib/medium/2425_bitwise_xor_of_all_pairings.rb)                                                   | [Link](./test/medium/test_2425_bitwise_xor_of_all_pairings.rb)                                                   |
 | 2429. Minimize XOR                                                                  | [Link](https://leetcode.com/problems/minimize-xor/)                                                                  | [Link](./lib/medium/2429_minimize_xor.rb)                                                                  | [Link](./test/medium/test_2429_minimize_xor.rb)                                                                  |

leetcode-ruby.gemspec

@@ -5,7 +5,7 @@ require 'English'
 ::Gem::Specification.new do |s|
   s.required_ruby_version = '>= 3.0'
   s.name = 'leetcode-ruby'
-  s.version = '8.9.1'
+  s.version = '8.9.2'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/2007_find_original_array_from_doubled_array.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/find-original-array-from-doubled-array/
+# @param {Integer[]} changed
+# @return {Integer[]}
+def find_original_array(changed)
+  result = []
+  q = []
+  changed.sort!
+
+  changed.each do |num|
+    if !q.empty? && num == q.first
+      q.shift
+    else
+      q << num * 2
+      result << num
+    end
+  end
+
+  q.empty? ? result : []
+end

test/medium/test_2007_find_original_array_from_doubled_array.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/2007_find_original_array_from_doubled_array'
+require 'minitest/autorun'
+
+class FindOriginalArrayFromDoubledArrayTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      [1, 3, 4],
+      find_original_array(
+        [1, 3, 4, 2, 6, 8]
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      [],
+      find_original_array(
+        [6, 3, 0, 1]
+      )
+    )
+  end
+
+  def test_default_three
+    assert_equal(
+      [],
+      find_original_array(
+        []
+      )
+    )
+  end
+end