2024-12-26 v. 7.5.1: added "725. Split Linked List in Parts"

Author: fartem

README.md

@@ -615,3 +615,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 707. Design Linked List                                         | [Link](https://leetcode.com/problems/design-linked-list/)                                         | [Link](./lib/medium/707_design_linked_list.rb)                                         | [Link](./test/medium/test_707_design_linked_list.rb)                                         |
 | 713. Subarray Product Less Than K                               | [Link](https://leetcode.com/problems/subarray-product-less-than-k/)                               | [Link](./lib/medium/713_subarray_product_less_than_k.rb)                               | [Link](./test/medium/test_713_subarray_product_less_than_k.rb)                               |
 | 720. Longest Word in Dictionary                                 | [Link](https://leetcode.com/problems/longest-word-in-dictionary/)                                 | [Link](./lib/medium/720_longest_word_in_dictionary.rb)                                 | [Link](./test/medium/test_720_longest_word_in_dictionary.rb)                                 |
+| 725. Split Linked List in Parts                                 | [Link](https://leetcode.com/problems/split-linked-list-in-parts/)                                 | [Link](./lib/medium/725_split_linked_list_in_parts.rb)                                 | [Link](./test/medium/test_725_split_linked_list_in_parts.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 = '7.5.0'
+  s.version = '7.5.1'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/common/linked_list.rb

@@ -30,6 +30,7 @@ def self.from_array(values)
   # @return {Boolean}
   def self.are_equals(first, second)
     return true if first.nil? && second.nil?
+
     return false if first.nil? || second.nil?
 
     first.val == second.val && are_equals(first.next, second.next)

lib/medium/725_split_linked_list_in_parts.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+require_relative '../common/linked_list'
+
+# https://leetcode.com/problems/split-linked-list-in-parts/
+# @param {ListNode} head
+# @param {Integer} k
+# @return {ListNode[]}
+def split_list_to_parts(head, k)
+  p = head
+  count = 0
+
+  until p.nil?
+    p = p.next
+    count += 1
+  end
+
+  part = count / k
+  remainder = count % k
+  result = []
+  p = head
+
+  (0...k).each do |i|
+    unit = ::ListNode.new(0)
+    curr = unit
+
+    (0...(part + (i < remainder ? 1 : 0))).each do |_|
+      next unless p
+
+      curr = curr.next = ::ListNode.new(p.val)
+      p = p.next
+    end
+
+    result << unit.next
+  end
+
+  result
+end

test/medium/test_725_split_linked_list_in_parts.rb

@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/linked_list'
+require_relative '../../lib/medium/725_split_linked_list_in_parts'
+require 'minitest/autorun'
+
+class SplitLinkedListInPartsTest < ::Minitest::Test
+  def test_default_one
+    result = split_list_to_parts(
+      ::ListNode.from_array(
+        [1, 2, 3]
+      ),
+      5
+    )
+
+    assert_equal(5, result.size)
+
+    [
+      ::ListNode.from_array([1]),
+      ::ListNode.from_array([2]),
+      ::ListNode.from_array([3]),
+      ::ListNode.from_array([]),
+      ::ListNode.from_array([])
+    ].each_with_index do |list, index|
+      assert(
+        ::ListNode.are_equals(
+          list,
+          result[index]
+        )
+      )
+    end
+  end
+
+  def test_default_two
+    result = split_list_to_parts(
+      ::ListNode.from_array(
+        [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+      ),
+      3
+    )
+
+    assert_equal(3, result.size)
+
+    [
+      ::ListNode.from_array(
+        [1, 2, 3, 4]
+      ),
+      ::ListNode.from_array(
+        [5, 6, 7]
+      ),
+      ::ListNode.from_array(
+        [8, 9, 10]
+      )
+    ].each_with_index do |list, index|
+      assert(
+        ::ListNode.are_equals(
+          list,
+          result[index]
+        )
+      )
+    end
+  end
+end