From 570218f749d721e8e1cf721bbd8532ab54a824ba Mon Sep 17 00:00:00 2001
From: fartem <jaman.smlnsk@gmail.com>
Date: Mon, 3 Mar 2025 09:06:39 +0300
Subject: [PATCH] 2025-03-03 v. 8.7.8: added "1685. Sum of Absolute Differences
 in a Sorted Array"

---
 README.md                                     |  1 +
 leetcode-ruby.gemspec                         |  2 +-
 ..._absolute_differences_in_a_sorted_array.rb | 23 +++++++++++++++++
 ..._absolute_differences_in_a_sorted_array.rb | 25 +++++++++++++++++++
 4 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 lib/medium/1685_sum_of_absolute_differences_in_a_sorted_array.rb
 create mode 100644 test/medium/test_1685_sum_of_absolute_differences_in_a_sorted_array.rb

diff --git a/README.md b/README.md
index 9027c372..3a6e0ce2 100644
--- a/README.md
+++ b/README.md
@@ -711,6 +711,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 1669. Merge In Between Linked Lists                                                 | [Link](https://leetcode.com/problems/merge-in-between-linked-lists/)                                                 | [Link](./lib/medium/1669_merge_in_between_linked_lists.rb)                                                 | [Link](./test/medium/test_1669_merge_in_between_linked_lists.rb)                                                 |
 | 1670. Design Front Middle Back Queue                                                | [Link](https://leetcode.com/problems/design-front-middle-back-queue/)                                                | [Link](./lib/medium/1670_design_front_middle_back_queue.rb)                                                | [Link](./test/medium/test_1670_design_front_middle_back_queue.rb)                                                |
 | 1679. Max Number of K-Sum Pairs                                                     | [Link](https://leetcode.com/problems/max-number-of-k-sum-pairs/)                                                     | [Link](./lib/medium/1679_max_number_of_k_sum_pairs.rb)                                                     | [Link](./test/medium/test_1679_max_number_of_k_sum_pairs.rb)                                                     |
+| 1685. Sum of Absolute Differences in a Sorted Array                                 | [Link](https://leetcode.com/problems/sum-of-absolute-differences-in-a-sorted-array/)                                 | [Link](./lib/medium/1685_sum_of_absolute_differences_in_a_sorted_array.rb)                                 | [Link](./test/medium/test_1685_sum_of_absolute_differences_in_a_sorted_array.rb)                                 |
 | 2116. Check if a Parentheses String Can Be Valid                                    | [Link](https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid/)                                    | [Link](./lib/medium/2116_check_if_a_parentheses_string_can_be_valid.rb)                                    | [Link](./test/medium/test_2116_check_if_a_parentheses_string_can_be_valid.rb)                                    |
 | 2425. Bitwise XOR of All Pairings                                                   | [Link](https://leetcode.com/problems/bitwise-xor-of-all-pairings/)                                                   | [Link](./lib/medium/2425_bitwise_xor_of_all_pairings.rb)                                                   | [Link](./test/medium/test_2425_bitwise_xor_of_all_pairings.rb)                                                   |
 | 2429. Minimize XOR                                                                  | [Link](https://leetcode.com/problems/minimize-xor/)                                                                  | [Link](./lib/medium/2429_minimize_xor.rb)                                                                  | [Link](./test/medium/test_2429_minimize_xor.rb)                                                                  |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 6af3b42e..acfa1379 100644
--- a/leetcode-ruby.gemspec
+++ b/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 = '8.7.7'
+  s.version = '8.7.8'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'
diff --git a/lib/medium/1685_sum_of_absolute_differences_in_a_sorted_array.rb b/lib/medium/1685_sum_of_absolute_differences_in_a_sorted_array.rb
new file mode 100644
index 00000000..c3750625
--- /dev/null
+++ b/lib/medium/1685_sum_of_absolute_differences_in_a_sorted_array.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/sum-of-absolute-differences-in-a-sorted-array/
+# @param {Integer[]} nums
+# @return {Integer[]}
+def get_sum_absolute_differences(nums)
+  size = nums.size
+
+  (1...size).each { |i| nums[i] += nums[i - 1] }
+
+  result = ::Array.new(size)
+  result[0] = nums[size - 1] - size * nums[0]
+
+  (1...size).each do |i|
+    left = nums[i - 1]
+    right = nums[size - 1] - nums[i]
+    current = nums[i] - left
+
+    result[i] = i * current - left + right - (size - i - 1) * current
+  end
+
+  result
+end
diff --git a/test/medium/test_1685_sum_of_absolute_differences_in_a_sorted_array.rb b/test/medium/test_1685_sum_of_absolute_differences_in_a_sorted_array.rb
new file mode 100644
index 00000000..4945c936
--- /dev/null
+++ b/test/medium/test_1685_sum_of_absolute_differences_in_a_sorted_array.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/1685_sum_of_absolute_differences_in_a_sorted_array'
+require 'minitest/autorun'
+
+class SumOfAbsoluteDifferencesInASortedArrayTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      [4, 3, 5],
+      get_sum_absolute_differences(
+        [2, 3, 5]
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      [24, 15, 13, 15, 21],
+      get_sum_absolute_differences(
+        [1, 4, 6, 8, 10]
+      )
+    )
+  end
+end