Merge pull request #748 from fartem/299_Bulls_and_Cows

2024-10-15 v. 6.8.1: added "299. Bulls and Cows"

Author: fartem

README.md

@@ -546,3 +546,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 240. Search a 2D Matrix II                                      | [Link](https://leetcode.com/problems/search-a-2d-matrix-ii/)                                      | [Link](./lib/medium/240_search_a_2d_matrix_ii.rb)                                      | [Link](./test/medium/test_240_search_a_2d_matrix_ii.rb)                                      |
 | 284. Peeking Iterator                                           | [Link](https://leetcode.com/problems/peeking-iterator/)                                           | [Link](./lib/medium/284_peeking_iterator.rb)                                           | [Link](./test/medium/test_284_peeking_iterator.rb)                                           |
 | 287. Find the Duplicate Number                                  | [Link](https://leetcode.com/problems/find-the-duplicate-number/)                                  | [Link](./lib/medium/287_find_the_duplicate_number.rb)                                  | [Link](./test/medium/test_287_find_the_duplicate_number.rb)                                  |
+| 299. Bulls and Cows                                             | [Link](https://leetcode.com/problems/bulls-and-cows/)                                             | [Link](./lib/medium/299_bulls_and_cows.rb)                                             | [Link](./test/medium/test_299_bulls_and_cows.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 = '6.8.0'
+  s.version = '6.8.1'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/299_bulls_and_cows.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/bulls-and-cows/
+# @param {String} secret
+# @param {String} guess
+# @return {String}
+def get_hint(secret, guess)
+  bulls = 0
+  cows = 0
+  map = ::Hash.new(0)
+
+  secret.chars.each_with_index do |s, i|
+    if s == guess[i]
+      bulls += 1
+    else
+      map[s] += 1
+    end
+  end
+
+  guess.chars.each_with_index do |g, i|
+    if g != secret[i] && map[g].positive?
+      cows += 1
+      map[g] -= 1
+    end
+  end
+
+  "#{bulls}A#{cows}B"
+end

test/medium/test_299_bulls_and_cows.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/299_bulls_and_cows'
+require 'minitest/autorun'
+
+class BullsAndCowsTest < ::Minitest::Test
+  def test_default_one = assert_equal('1A3B', get_hint('1807', '7810'))
+
+  def test_default_two = assert_equal('1A1B', get_hint('1123', '0111'))
+end