diff --git a/README.md b/README.md
index 118482ac..ac343fad 100644
--- a/README.md
+++ b/README.md
@@ -126,3 +126,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 589. N-ary Tree Preorder Traversal                     | [Link](https://leetcode.com/problems/n-ary-tree-preorder-traversal/)                      | [Link](./lib/easy/589_n_ary_tree_preorder_traversal.rb)                     |
 | 590. N-ary Tree Postorder Traversal                    | [Link](https://leetcode.com/problems/n-ary-tree-postorder-traversal/)                     | [Link](./lib/easy/590_n_ary_tree_postorder_traversal.rb)                    |
 | 594. Longest Harmonious Subsequence                    | [Link](https://leetcode.com/problems/longest-harmonious-subsequence/)                     | [Link](./lib/easy/594_longest_harmonious_subsequence.rb)                    |
+| 599. Minimum Index Sum of Two Lists                    | [Link](https://leetcode.com/problems/minimum-index-sum-of-two-lists/)                     | [Link](./lib/easy/599_minimum_index_sum_of_two_lists.rb)                    |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 540dc94c..e3453904 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 = '1.2.0'
+  s.version = '1.2.1'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'
diff --git a/lib/easy/599_minimum_index_sum_of_two_lists.rb b/lib/easy/599_minimum_index_sum_of_two_lists.rb
new file mode 100644
index 00000000..96ef9733
--- /dev/null
+++ b/lib/easy/599_minimum_index_sum_of_two_lists.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/minimum-index-sum-of-two-lists/
+# @param {String[]} list1
+# @param {String[]} list2
+# @return {String[]}
+def find_restaurant(list1, list2)
+  list1_map = {}
+  list1.each_with_index { |val, index| list1_map[val] = index }
+  min = 1_000_000
+  result = []
+  list2.each_with_index do |val, index|
+    next unless list1_map.include?(val)
+
+    sum = index + list1_map[val]
+    next unless sum <= min
+
+    result.clear if sum != min
+    min = sum
+    result << val
+  end
+
+  result
+end
diff --git a/test/easy/test_599_minimum_index_sum_of_two_lists.rb b/test/easy/test_599_minimum_index_sum_of_two_lists.rb
new file mode 100644
index 00000000..b1089405
--- /dev/null
+++ b/test/easy/test_599_minimum_index_sum_of_two_lists.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/easy/599_minimum_index_sum_of_two_lists'
+require 'minitest/autorun'
+
+class MinimumIndexSumOfTwoListsTest < ::Minitest::Test
+  def test_default
+    assert_equal(
+      ['Shogun'],
+      find_restaurant(
+        ['Shogun', 'Tapioca Express', 'Burger King', 'KFC'],
+        ['Piatti', 'The Grill at Torrey Pines', 'Hungry Hunter Steakhouse', 'Shogun']
+      )
+    )
+    assert_equal(
+      ['Shogun'],
+      find_restaurant(
+        ['Shogun', 'Tapioca Express', 'Burger King', 'KFC'],
+        ['KFC', 'Shogun', 'Burger King']
+      )
+    )
+    assert_equal(
+      %w[sad happy],
+      find_restaurant(
+        %w[happy sad good],
+        %w[sad happy good]
+      )
+    )
+  end
+end