2024-07-05 v. 6.0.5: added "22. Generate Parentheses"

Author: fartem

README.md

@@ -470,3 +470,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 16. 3Sum Closest                                  | [Link](https://leetcode.com/problems/3sum-closest/)                                   | [Link](./lib/medium/16_3sum_closest.rb)                                  |
 | 17. Letter Combinations of a Phone Number         | [Link](https://leetcode.com/problems/letter-combinations-of-a-phone-number/)          | [Link](./lib/medium/17_letter_combinations_of_a_phone_number.rb)         |
 | 19. Remove Nth Node From End of List              | [Link](https://leetcode.com/problems/remove-nth-node-from-end-of-list/)               | [Link](./lib/medium/19_remove_nth_node_from_end_of_list.rb)              |
+| 22. Generate Parentheses                          | [Link](https://leetcode.com/problems/generate-parentheses/)                           | [Link](./lib/medium/22_generate_parentheses.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 = '6.0.4'
+  s.version = '6.0.5'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'

lib/medium/22_generate_parentheses.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/generate-parentheses/
+# @param {Integer} n
+# @return {String[]}
+def generate_parenthesis(n)
+  result = []
+  result << '' if n.zero?
+  (0...n).each do |i|
+    generate_parenthesis(i).each do |left|
+      generate_parenthesis(n - 1 - i).each do |right|
+        result << "(#{left})#{right}"
+      end
+    end
+  end
+
+  result
+end

test/medium/test_22_generate_parentheses.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/22_generate_parentheses'
+require 'minitest/autorun'
+
+class GenerateParenthesesTest < ::Minitest::Test
+  def test_default
+    assert_equal(
+      %w[()()() ()(()) (())() (()()) ((()))],
+      generate_parenthesis(3)
+    )
+    assert_equal(['()'], generate_parenthesis(1))
+  end
+end