| author | Christian Urban <christian dot urban at kcl dot ac dot uk> |
| Sat, 29 Oct 2016 21:45:44 +0100 | |
| changeset 467 | b5ec11e89768 |
| parent 448 | 96129128d0f1 |
| child 538 | 17acdd516ccd |
| 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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m = re.match('(a*)*b' , "a" * int(cn))
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print m.group(0) |