| author | Christian Urban <christian dot urban at kcl dot ac dot uk> |
| Fri, 24 Jul 2020 12:58:19 +0100 | |
| changeset 738 | 03f46065ef04 |
| parent 538 | e03107e79d26 |
| permissions | -rwxr-xr-x |
| 448 | 1 |
#!/usr/bin/env python |
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import re |
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import sys |
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# case of catastrophic backtracking in Python |
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# |
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# regex: (a*)*b |
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# strings: aa...a |
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# |
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# call with timing as: |
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# |
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# > time ./catastrophic.py 20 |
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# counter n given on the command line |
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cn = sys.argv[1] |
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# calling the matching function |
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s = ("a" * int(cn))
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m = re.match('(a*)*b' , s)
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print s |