Merge pull request #654 from fartem/7_Reverse_Integer

2024-06-26 v. 5.9.7: added "7. Reverse Integer"

Author: fartem

README.md

@@ -462,3 +462,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 2. Add Two Numbers                                | [Link](https://leetcode.com/problems/add-two-numbers/)                                | [Link](./lib/medium/2_add_two_numbers.rb)                                |
 | 3. Longest Substring Without Repeating Characters | [Link](https://leetcode.com/problems/longest-substring-without-repeating-characters/) | [Link](./lib/medium/3_longest_substring_without_repeating_characters.rb) |
 | 5. Longest Palindromic Substring                  | [Link](https://leetcode.com/problems/longest-palindromic-substring/)                  | [Link](./lib/medium/5_longest_palindromic_substring.rb)                  |
+| 7. Reverse Integer                                | [Link](https://leetcode.com/problems/reverse-integer/)                                | [Link](./lib/medium/7_reverse_integer.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 = '5.9.6'
+  s.version = '5.9.7'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'

lib/medium/7_reverse_integer.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/reverse-integer/
+# @param {Integer} x
+# @return {Integer}
+def reverse7(x)
+  num = x.to_s.reverse.to_i
+
+  return 0 if num > 2**31 - 1
+
+  x.negative? ? -num : num
+end

test/medium/test_7_reverse_integer.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/7_reverse_integer'
+require 'minitest/autorun'
+
+class ReverseIntegerTest < ::Minitest::Test
+  def test_default
+    assert_equal(321, reverse7(123))
+    assert_equal(-321, reverse7(-123))
+    assert_equal(21, reverse7(120))
+  end
+
+  def test_additional
+    assert_equal(0, reverse7(2**31))
+  end
+end