Merge pull request #709 from fartem/128_Longest_Consecutive_Sequence

2024-08-14 v. 6.4.7: added "128. Longest Consecutive Sequence"

Author: fartem

README.md

@@ -512,3 +512,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 116. Populating Next Right Pointers in Each Node                | [Link](https://leetcode.com/problems/populating-next-right-pointers-in-each-node/)                | [Link](./lib/medium/116_populating_next_right_pointers_in_each_node.rb)                |
 | 117. Populating Next Right Pointers in Each Node II             | [Link](https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/)             | [Link](./lib/medium/117_populating_next_right_pointers_in_each_node_ii.rb)             |
 | 120. Triangle                                                   | [Link](https://leetcode.com/problems/triangle/)                                                   | [Link](./lib/medium/120_triangle.rb)                                                   |
+| 128. Longest Consecutive Sequence                               | [Link](https://leetcode.com/problems/longest-consecutive-sequence/)                               | [Link](./lib/medium/128_longest_consecutive_sequence.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 = '6.4.6'
+  s.version = '6.4.7'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/128_longest_consecutive_sequence.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+require 'set'
+
+# https://leetcode.com/problems/longest-consecutive-sequence/
+# @param {Integer[]} nums
+# @return {Integer}
+def longest_consecutive(nums)
+  uniq = nums.to_set
+  result = 0
+  uniq.each do |num|
+    next if uniq.include?(num - 1)
+
+    curr = num
+    count = 1
+    while uniq.include?(curr + 1)
+      curr += 1
+      count += 1
+    end
+
+    result = [result, count].max
+  end
+
+  result
+end

test/medium/test_128_longest_consecutive_sequence.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/128_longest_consecutive_sequence'
+require 'minitest/autorun'
+
+class LongestConsequtiveSequenceTest < ::Minitest::Test
+  def test_default
+    assert_equal(4, longest_consecutive([100, 4, 200, 1, 3, 2]))
+    assert_equal(9, longest_consecutive([0, 3, 7, 2, 5, 8, 4, 6, 0, 1]))
+  end
+end