2024-07-24 v. 6.3.0: added "86. Partition List"

Author: fartem

README.md

@@ -495,3 +495,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 75. Sort Colors                                             | [Link](https://leetcode.com/problems/sort-colors/)                                             | [Link](./lib/medium/75_sort_colors.rb)                                             |
 | 78. Subsets                                                 | [Link](https://leetcode.com/problems/subsets/)                                                 | [Link](./lib/medium/78_subsets.rb)                                                 |
 | 82. Remove Duplicates from Sorted List II                   | [Link](https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/)                   | [Link](./lib/medium/82_remove_duplicates_from_sorted_list_ii.rb)                   |
+| 86. Partition List                                          | [Link](https://leetcode.com/problems/partition-list/)                                          | [Link](./lib/medium/86_partition_list.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 = '6.2.9'
+  s.version = '6.3.0'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/86_partition_list.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require_relative '../common/linked_list'
+
+# https://leetcode.com/problems/partition-list/
+# @param {ListNode} head
+# @param {Integer} x
+# @return {ListNode}
+def partition(head, x)
+  f = ::ListNode.new
+  f_p = f
+  s = ::ListNode.new
+  s_p = s
+
+  until head.nil?
+    if head.val < x
+      f_p.next = ::ListNode.new(head.val)
+      f_p = f_p.next
+    else
+      s_p.next = ::ListNode.new(head.val)
+      s_p = s_p.next
+    end
+
+    head = head.next
+  end
+
+  f_p&.next = s.next
+
+  f.next
+end

test/medium/test_86_partition_list.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/linked_list'
+require_relative '../../lib/medium/86_partition_list'
+require 'minitest/autorun'
+
+class PartitionListTest < ::Minitest::Test
+  def test_default
+    assert(
+      ::ListNode.are_equals(
+        ::ListNode.from_array(
+          [1, 2, 2, 4, 3, 5]
+        ),
+        partition(
+          ::ListNode.from_array(
+            [1, 4, 3, 2, 5, 2]
+          ),
+          3
+        )
+      )
+    )
+    assert(
+      ::ListNode.are_equals(
+        ::ListNode.from_array([1, 2]),
+        partition(
+          ::ListNode.from_array([2, 1]),
+          2
+        )
+      )
+    )
+  end
+end