Merge pull request #652 from fartem/3_Longest_Substring_Without_Repeating_Characters

2024-06-24 v. 5.9.5: added "3. Longest Substring Without Repeating Characters"

Author: fartem

README.md

@@ -457,6 +457,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 
 ### Medium
 
-| Name               | Link to LeetCode                                       | Link to solution                          |
-|--------------------|--------------------------------------------------------|-------------------------------------------|
-| 2. Add Two Numbers | [Link](https://leetcode.com/problems/add-two-numbers/) | [Link](./lib/medium/2_add_two_numbers.rb) |
+| Name                                              | Link to LeetCode                                                                      | Link to solution                                                         |
+|---------------------------------------------------|---------------------------------------------------------------------------------------|--------------------------------------------------------------------------|
+| 2. Add Two Numbers                                | [Link](https://leetcode.com/problems/add-two-numbers/)                                | [Link](./lib/medium/2_add_two_numbers.rb)                                |
+| 3. Longest Substring Without Repeating Characters | [Link](https://leetcode.com/problems/longest-substring-without-repeating-characters/) | [Link](./lib/medium/3_longest_substring_without_repeating_characters.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 = '5.9.4'
+  s.version = '5.9.5'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'

lib/medium/3_longest_substring_without_repeating_characters.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/longest-substring-without-repeating-characters/
+# @param {String} s
+# @return {Integer}
+def length_of_longest_substring(s)
+  last_index = ::Array.new(256, -1)
+  index = 0
+  result = 0
+  (0...s.length).each do |i|
+    c = s[i].ord
+    index = [index, last_index[c] + 1].max
+    result = [result, i - index + 1].max
+    last_index[c] = i
+  end
+
+  result
+end

test/medium/test_3_longest_substring_without_repeating_characters.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/3_longest_substring_without_repeating_characters'
+require 'minitest/autorun'
+
+class LongestSubstringWithoutRepeatingCharactersTest < ::Minitest::Test
+  def test_default
+    assert_equal(3, length_of_longest_substring('abcabcbb'))
+    assert_equal(1, length_of_longest_substring('bbbbb'))
+    assert_equal(3, length_of_longest_substring('pwwkew'))
+  end
+end