Levenstein Distance

Levenstein distance is a measure of distance between two string.
Intuitive defintion is the minimum number of modifications required to obtain string b from the given string a

The python implementation of the algorithm is the following.

def edit_distance(str1,str2,m,n):
  
  if m==0:
    return n
  elif n==0:
    return m
  elif str1[m-1]==str2[n-1]:
    return edit_distance(str1,str2,m-1,n-1)
  else:
    return 1+min(

      edit_distance(str1,str2,m,n-1), # This is insert operation
      edit_distance(str1,str2,m-1,n), # this is remove opeartion
      edit_distance(str1,str2,m-1,n-1) # this is replace operation

    )

The logic of the algorithm is to caluclate the minimum number of , delets, and insertions, and replacements required to obtain string A from string A.