39 lines
999 B
Python
39 lines
999 B
Python
#!/usr/bin/env python
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"""
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This example shows how to use the function generate_hash.
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generate_hash(kdic, Hash)
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returns hash functions f1 and f2, and G for a perfect minimal hash.
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Input is dictionary 'kdic' with the keys and desired hash values.
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'Hash' is a random hash function generator, that means Hash(N) returns a
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returns a random hash function which returns hash values from 0..N-1.
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"""
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import sys
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import random, string
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sys.path.append('..')
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from perfect_hash import generate_hash
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month = dict(zip('jan feb mar apr may jun jul aug sep oct mov dec'.split(),
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range(1, 13)))
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def mkRandHash(N):
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"""
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Return a random hash function which returns hash values from 0..N-1.
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"""
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junk = "".join(random.choice(string.letters + string.digits)
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for i in xrange(10))
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return lambda key: hash(junk + str(key)) % N
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f1, f2, G = generate_hash(month, mkRandHash)
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for k, h in month.items():
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assert h == ( G[f1(k)] + G[f2(k)] ) % len(G)
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print 'OK'
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