2024-10-08 v. 6.7.7: added "238. Product of Array Except Self"

Author: fartem

README.md

@@ -542,3 +542,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 235. Lowest Common Ancestor of a Binary Search Tree             | [Link](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/)             | [Link](./lib/medium/235_lowest_common_ancestor_of_a_binary_search_tree.rb)             | [Link](./test/medium/test_235_lowest_common_ancestor_of_a_binary_search_tree.rb)             |
 | 236. Lowest Common Ancestor of a Binary Tree                    | [Link](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/)                    | [Link](./lib/medium/236_lowest_common_ancestor_of_a_binary_tree.rb)                    | [Link](./test/medium/test_236_lowest_common_ancestor_of_a_binary_tree.rb)                    |
 | 237. Delete Node in a Linked List                               | [Link](https://leetcode.com/problems/delete-node-in-a-linked-list/)                               | [Link](./lib/medium/237_delete_node_in_a_linked_list.rb)                               | [Link](./test/medium/test_237_delete_node_in_a_linked_list.rb)                               |
+| 238. Product of Array Except Self                               | [Link](https://leetcode.com/problems/product-of-array-except-self/)                               | [Link](./lib/medium/238_product_of_array_except_self.rb)                               | [Link](./test/medium/test_238_product_of_array_except_self.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 = '6.7.6'
+  s.version = '6.7.7'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/238_product_of_array_except_self.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/product-of-array-except-self/
+# @param {Integer[]} nums
+# @return {Integer[]}
+def product_except_self(nums)
+  mul = 1
+  zeros = 0
+
+  nums.each do |num|
+    zeros += num.zero? ? 1 : 0
+    mul *= num.zero? ? 1 : num
+  end
+
+  return ::Array.new(nums.length, 0) if zeros > 1
+
+  (0...nums.length).each do |i|
+    num = nums[i]
+    nums[i] =
+      if zeros.zero?
+        nums[i] = mul / num
+      else
+        num.zero? ? mul : 0
+      end
+  end
+
+  nums
+end

test/medium/test_238_product_of_array_except_self.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/238_product_of_array_except_self'
+require 'minitest/autorun'
+
+class ProductOfArrayExceptSelfTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      [24, 12, 8, 6],
+      product_except_self(
+        [1, 2, 3, 4]
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      [0, 0, 9, 0, 0],
+      product_except_self(
+        [-1, 1, 0, -3, 3]
+      )
+    )
+  end
+end