Data commit

Task/Balanced-brackets/Ruby/balanced-brackets.rb

@@ -0,0 +1,17 @@
+re = /\A     # beginning of string
+  (?<bb>     # begin capture group <bb>
+    \[       #   literal [
+    \g<bb>*  #   zero or more <bb>
+    \]       #   literal ]
+  )*         # end group, zero or more such groups
+\z/x         # end of string
+
+10.times do |i|
+  s = (%w{[ ]} * i).shuffle.join
+  puts (s =~ re ? " OK: " : "bad: ") + s
+end
+
+["[[]", "[]]", "a[ letters[-1] ].xyz[0]"].each do |s|
+  t = s.gsub(/[^\[\]]/, "")
+  puts (t =~ re ? " OK: " : "bad: ") + s
+end