--- a/progs/catastrophic.rb Mon Jul 27 01:55:05 2020 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,35 +0,0 @@
-# A case of catastrophic backtracking in Ruby
-#---------------------------------------------
-# example provided by Daniel Baldwin
-#
-#
-# regex: (a?){n} a{n}
-# strings: aa...
-#
-# run on the command line with:
-#
-# $> ruby catastrophic.rb
-#
-
-nums = (1..1000)
-
-#iterate through the nums 1-1000
-nums.each do |i|
-
- start_time = Time.now
- string = "a" * i
-
- #create a new regular expression based on current value of i
- re_str = "a?" * i + "+" + "a" * i
- re = Regexp.new(re_str)
-
- re.match(string)
-
- #if re.match(string)
- # puts "matched string a * #{i} with regex #{re}"
- #else
- # puts "unmatched string a * #{i} with regex #{re}"
- #end
-
- puts "#{i} %.5f" % (Time.now - start_time)
-end