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61 lines
1.7 KiB
Python
61 lines
1.7 KiB
Python
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#coding: utf-8
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''' mbinary
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#######################################################################
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# File : hammingDistance.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: 2018-12-17 17:36
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# Description:
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hamming distance is the number of different position (or binary bit for number) of two strings.
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eg 'abac', 'ab': 2 1010,11 : 3
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#######################################################################
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'''
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def hammingDistance(a,b):
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if isinstance(a,int):
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n = a^b
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ct = 0
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while n:
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ct+=n%2
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n>>=1
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return ct
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else:
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n,m = len(a),len(b)
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ret = 0
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for i,j in zip(a,b):
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ret+= i==j
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return ret+abs(n-m)
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def totalHammingDistance(lst):
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'''return sum of any two items(num or lst( str)) in lst'''
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length = len(lst)
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if length ==0:return 0
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if isinstance(lst[0],int):
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bits = [0] * len(bin(max(lst)))
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for n in lst:
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ct = 0
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while n:
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if n%2==1:
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bits[ct]+=1
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ct+=1
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n>>=1
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return sum(i*(length-i) for i in bits)
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else:
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mx = len(max(lst,key=len))
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position = [dict() for i in range(mx)]
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for li in lst:
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for i,x in enumerate(li):
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if x in position[i]:
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position[i][x] +=1
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else:
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position[i][x] =1
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ret = 0
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for dic in position:
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left = length
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for i in dic.values():
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ret+=i*(left-i) # key step
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left -=i # key step
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return ret
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