input: Write a function to compute the edit distance between two given strings in Python. The function should return the minimum number of operations (insertions, deletions, or substitutions) required to transform string1 into string2. The function takes two strings and their lengths as arguments and returns the edit distance.
  
  assert editDistance("kitten", "sitting", len("kitten"), len("sitting")) == 3
  assert editDistance("intention", "execution", len("intention"), len("execution")) == 5
  assert editDistance("cat", "bat", len("cat"), len("bat")) == 1
  assert editDistance("horse", "ros", len("horse"), len("ros")) == 3
  assert editDistance("", "", len(""), len("")) == 0
output: def editDistance(str1, str2, m, n):
      if m == 0:
          return n
      if n == 0:
          return m
      if str1[m-1] == str2[n-1]:
          return editDistance(str1, str2, m-1, n-1)
      return 1 + min(editDistance(str1, str2, m, n-1),    # Insert
                     editDistance(str1, str2, m-1, n),    # Remove
                     editDistance(str1, str2, m-1, n-1))  # Replace