2025-01-14 v. 8.0.4: added "1220. Count Vowels Permutation"

Author: fartem

README.md

@@ -673,3 +673,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 936. Stamping The Sequence                    | [Link](https://leetcode.com/problems/stamping-the-sequence/)                     | [Link](./lib/hard/936_stamping_the_sequence.rb)                    | [Link](./test/hard/test_936_stamping_the_sequence.rb)                    |
 | 968. Binary Tree Cameras                      | [Link](https://leetcode.com/problems/binary-tree-cameras/)                       | [Link](./lib/hard/968_binary_tree_cameras.rb)                      | [Link](./test/hard/test_968_binary_tree_cameras.rb)                      |
 | 1106. Parsing A Boolean Expression            | [Link](https://leetcode.com/problems/parsing-a-boolean-expression/)              | [Link](./lib/hard/1106_parsing_a_boolean_expression.rb)            | [Link](./test/hard/test_1106_parsing_a_boolean_expression.rb)            |
+| 1220. Count Vowels Permutation                | [Link](https://leetcode.com/problems/count-vowels-permutation/)                  | [Link](./lib/hard/1220_count_vowels_permutation.rb)                | [Link](./test/hard/test_1220_count_vowels_permutation.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 = '8.0.3'
+  s.version = '8.0.4'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/hard/1220_count_vowels_permutation.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: false
+
+# https://leetcode.com/problems/count-vowels-permutation/
+# @param {Integer} n
+# @return {Integer}
+def count_vowel_permutation(n)
+  a = 1
+  e = 1
+  i = 1
+  o = 1
+  u = 1
+  mod = 10**9 + 7
+
+  (2..n).each do
+    a2 = (e + i + u) % mod
+    e2 = (a + i) % mod
+    i2 = (e + o) % mod
+    o2 = i
+    u2 = (o + i) % mod
+
+    a = a2
+    e = e2
+    i = i2
+    o = o2
+    u = u2
+  end
+
+  (a + e + i + o + u) % mod
+end

test/hard/test_1220_count_vowels_permutation.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: false
+
+require_relative '../test_helper'
+require_relative '../../lib/hard/1220_count_vowels_permutation'
+require 'minitest/autorun'
+
+class CountVowelsPermutationTest < ::Minitest::Test
+  def test_default_one = assert(5, count_vowel_permutation(1))
+
+  def test_default_two = assert(10, count_vowel_permutation(2))
+
+  def test_default_three = assert(68, count_vowel_permutation(5))
+end