Merge pull request #1030 from fartem/2678-Number-of-Senior-Citizens

2025-06-03 v. 9.3.8: added "2678. Number of Senior Citizens"

Author: fartem

README.md

@@ -457,6 +457,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 2951. Find the Peaks                                               | [Link](https://leetcode.com/problems/find-the-peaks/)                                               | [Link](./lib/easy/2951_find_the_peaks.rb)                                               | [Link](./test/easy/test_2951_find_the_peaks.rb)                                               |
 | 2966. Divide Array Into Arrays With Max Difference                 | [Link](https://leetcode.com/problems/divide-array-into-arrays-with-max-difference/)                 | [Link](./lib/easy/2966_divide_array_into_arrays_with_max_difference.rb)                 | [Link](./test/easy/test_2966_divide_array_into_arrays_with_max_difference.rb)                 |
 | 2974. Minimum Number Game                                          | [Link](https://leetcode.com/problems/minimum-number-game/)                                          | [Link](./lib/easy/2974_minimum_number_game.rb)                                          | [Link](./test/easy/test_2974_minimum_number_game.rb)                                          |
+| 2678. Number of Senior Citizens                                    | [Link](https://leetcode.com/problems/number-of-senior-citizens/)                                    | [Link](./lib/easy/2678_number_of_senior_citizens.rb)                                    | [Link](./test/easy/test_2678_number_of_senior_citizens.rb)                                    |
 | 3046. Split the Array                                              | [Link](https://leetcode.com/problems/split-the-array/)                                              | [Link](./lib/easy/3046_split_the_array.rb)                                              | [Link](./test/easy/test_3046_split_the_array.rb)                                              |
 | 3083. Existence of a Substring in a String and Its Reverse         | [Link](https://leetcode.com/problems/existence-of-a-substring-in-a-string-and-its-reverse/)         | [Link](./lib/easy/3083_existence_of_a_substring_in_a_string_and_its_reverse.rb)         | [Link](./test/easy/test_3083_existence_of_a_substring_in_a_string_and_its_reverse.rb)         |
 | 3090. Maximum Length Substring With Two Occurrences                | [Link](https://leetcode.com/problems/maximum-length-substring-with-two-occurrences/)                | [Link](./lib/easy/3090_maximum_length_substring_with_two_occurrences.rb)                | [Link](./test/easy/test_3090_maximum_length_substring_with_two_occurrences.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 = '9.3.7.1'
+  s.version = '9.3.8'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/easy/2678_number_of_senior_citizens.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/number-of-senior-citizens/
+# @param {String[]} details
+# @return {Integer}
+def count_seniors(details)
+  details.count { |detail| detail[11..12] > '60' }
+end

test/easy/test_2678_number_of_senior_citizens.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/easy/2678_number_of_senior_citizens'
+require 'minitest/autorun'
+
+class NumberOfSeniorCitizensTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      2,
+      count_seniors(
+        %w[
+          7868190130M7522
+          5303914400F9211
+          9273338290F4010
+        ]
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      0,
+      count_seniors(
+        %w[
+          1313579440F2036
+          2921522980M564
+        ]
+      )
+    )
+  end
+end