diff --git a/README.md b/README.md
index d9450e47..12434293 100644
--- a/README.md
+++ b/README.md
@@ -142,3 +142,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 693. Binary Number with Alternating Bits               | [Link](https://leetcode.com/problems/binary-number-with-alternating-bits/)                | [Link](./lib/easy/693_binary_number_with_alternating_bits.rb)               |
 | 700. Search in a Binary Search Tree                    | [Link](https://leetcode.com/problems/search-in-a-binary-search-tree/)                     | [Link](./lib/easy/700_search_in_a_binary_search_tree.rb)                    |
 | 703. Kth Largest Element in a Stream                   | [Link](https://leetcode.com/problems/kth-largest-element-in-a-stream/)                    | [Link](./lib/easy/703_kth_largest_element_in_a_stream.rb)                   |
+| 704. Binary Search                                     | [Link](https://leetcode.com/problems/binary-search/)                                      | [Link](./lib/easy/704_binary_search.rb)                                     |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 09c3979b..1289ba0d 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 = '1.3.6.1'
+  s.version = '1.3.7'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'
diff --git a/lib/easy/704_binary_search.rb b/lib/easy/704_binary_search.rb
new file mode 100644
index 00000000..1c009490
--- /dev/null
+++ b/lib/easy/704_binary_search.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/binary-search/
+# @param {Integer[]} nums
+# @param {Integer} target
+# @return {Integer}
+def search(nums, target)
+  l = 0
+  r = nums.length - 1
+  while l <= r
+    m = l + (r - l) / 2
+    num = nums[m]
+
+    return m if num == target
+
+    if num < target
+      l = m + 1
+    else
+      r = m - 1
+    end
+  end
+
+  -1
+end
diff --git a/test/easy/test_704_binary_search.rb b/test/easy/test_704_binary_search.rb
new file mode 100644
index 00000000..0f8abede
--- /dev/null
+++ b/test/easy/test_704_binary_search.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/easy/704_binary_search'
+require 'minitest/autorun'
+
+class BinarySearchTest < ::Minitest::Test
+  def test_default
+    assert_equal(4, search([-1, 0, 3, 5, 9, 12], 9))
+    assert_equal(-1, search([-1, 0, 3, 5, 9, 12], 2))
+  end
+end