updated default tip
authorChristian Urban <christian.urban@kcl.ac.uk>
Tue, 18 Nov 2025 12:11:53 +0000
changeset 1028 803d5ece1c07
parent 1027 dadb5a94728d
updated
handouts/ho07.pdf
progs/catastrophic/catastrophic2.py
Binary file handouts/ho07.pdf has changed
--- a/progs/catastrophic/catastrophic2.py	Tue Nov 18 11:33:20 2025 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,22 +0,0 @@
-#!/usr/bin/env python3
-import re
-import sys
-
-# case of catastrophic backtracking in Python
-#
-# regex: (a*)*b
-# strings: aa...a
-#
-# call with timing as:
-#
-#    time ./catastrophic2.py 20
-
-# counter n given on the command line
-cn = sys.argv[1]
-
-# calling the matching function
-s = ("a" * int(cn))
-m = re.fullmatch('(a*)*b' , s) 
-
-print(s)
-print(bool(m))