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58 lines
1.5 KiB
Python
58 lines
1.5 KiB
Python
''' mbinary
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#########################################################################
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# File : sunday.py
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# Author: mbinary
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# Mail: zhuheqin1@gmail.com
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# Blog: https://mbinary.coding.me
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# Github: https://github.com/mbinary
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# Created Time: 2018-07-11 15:26
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# Description: 字符串模式匹配, sunday 算法, kmp 的改进
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# pattern matching for strings using sunday algorithm
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#########################################################################
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'''
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def getPos(pattern):
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dic = {}
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for i,j in enumerate(pattern[::-1]):
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if j not in dic:
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dic[j]= i
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return dic
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def find(s,p):
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dic = getPos(p)
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ps = pp = 0
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ns = len(s)
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np = len(p)
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while ps<ns and pp<np:
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if s[ps] == p[pp]:
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ps,pp = ps+1,pp+1
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else:
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idx = ps-pp+np
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if idx >=ns:return -1
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ch = s[idx]
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if ch in dic:
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ps += dic[ch]+1-pp
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else:
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ps += np-pp
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pp = 0
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if pp==np:return ps-np
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else:
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return -1
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def test():
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s = [randint(78,88) for i in range(30)]
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p = [randint(78,88) for i in range(3)]
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str_s = ''.join((chr(i) for i in s))
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str_p = ''.join((chr(i) for i in p))
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n1 = find(s,p)
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n2 = str_s.find(str_p)
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if n1!=n2:
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print(n1,n2,str_p,str_s)
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return False
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return True
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if __name__ =='__main__':
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from random import randint
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n = 10000
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suc = sum(test() for i in range(n))
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print(f'test {n} times, success {suc} times')
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