2025-04-21 v. 9.3.0: added "3090. Maximum Length Substring With Two Occurrences"

Author: fartem

README.md

@@ -456,6 +456,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 2652. Sum Multiples                                                | [Link](https://leetcode.com/problems/sum-multiples/)                                                | [Link](./lib/easy/2652_sum_multiples.rb)                                                | [Link](./test/easy/test_2652_sum_multiples.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)                                          |
 | 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)                |
 | 3110. Score of a String                                            | [Link](https://leetcode.com/problems/score-of-a-string/)                                            | [Link](./lib/easy/3110_score_of_a_string.rb)                                            | [Link](./test/easy/test_3110_score_of_a_string.rb)                                            |
 | 3131. Find the Integer Added to Array I                            | [Link](https://leetcode.com/problems/find-the-integer-added-to-array-i/)                            | [Link](./lib/easy/3131_find_the_integer_added_to_array_i.rb)                            | [Link](./test/easy/test_3131_find_the_integer_added_to_array_i.rb)                            |
 | 3136. Valid Word                                                   | [Link](https://leetcode.com/problems/valid-word/)                                                   | [Link](./lib/easy/3136_valid_word.rb)                                                   | [Link](./test/easy/test_3136_valid_word.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 = '9.2.9.1'
+  s.version = '9.3.0'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/easy/3090_maximum_length_substring_with_two_occurrences.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/maximum-length-substring-with-two-occurrences/
+# @param {String} s
+# @return {Integer}
+def maximum_length_substring(s)
+  max_len = 0
+  left = 0
+  char_count = ::Hash.new(0)
+
+  s.each_char.with_index do |char, right|
+    char_count[char] += 1
+
+    while char_count[char] > 2
+      char_count[s[left]] -= 1
+      left += 1
+    end
+
+    current_len = right - left + 1
+    max_len = [max_len, current_len].max
+  end
+
+  max_len
+end

test/easy/test_3090_maximum_length_substring_with_two_occurrences.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/easy/3090_maximum_length_substring_with_two_occurrences'
+require 'minitest/autorun'
+
+class MaximumLengthSubstringWithTwoOccurrencesTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      4,
+      maximum_length_substring(
+        'bcbbbcba'
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      2,
+      maximum_length_substring(
+        'aaaa'
+      )
+    )
+  end
+end