problem set + solution

lib/leetcode.rb

@@ -7,6 +7,7 @@
 require 'leetcode/reverse_nodes_in_k_group'
 require 'leetcode/median_of_two_sorted_arrays'
 require 'leetcode/regular_expression_matching'
+require 'leetcode/number_after_double_reversal'
 require 'leetcode/substring_with_concat_of_all_words'
 require 'leetcode/count_number_of_distinct_integers_after_reverse_operations'
 

lib/leetcode/number_after_double_reversal.rb

@@ -0,0 +1,7 @@
+module Leetcode
+  class NumberAfterDoubleReversal
+    def execute(num)
+      num.to_s.reverse.to_i.to_s.reverse.to_i == num
+    end
+  end
+end

spec/leetcode/number_after_double_reversal_spec.rb

@@ -0,0 +1,30 @@
+RSpec.describe Leetcode::NumberAfterDoubleReversal do
+  describe '#execute' do
+    let(:num) { nil }
+    subject { Leetcode::NumberAfterDoubleReversal.new.execute(num) }
+
+    context '526' do
+      let(:num) { 526 }
+
+      it do
+        expect(subject).to be true
+      end
+    end
+
+    context '1800' do
+      let(:num) { 1800 }
+
+      it do
+        expect(subject).to be false
+      end
+    end
+
+    context '0' do
+      let(:num) { 0 }
+
+      it do
+        expect(subject).to be true
+      end
+    end
+  end
+end