Leetcode: Generalized Abbreviation

Question

Write a function to generate the generalized abbreviations of a word.

Example:
Given word = “word”, return the following list (order does not matter):
[“word”, “1ord”, “w1rd”, “wo1d”, “wor1”, “2rd”, “w2d”, “wo2”, “1o1d”, “1or1”, “w1r1”, “1o2”, “2r1”, “3d”, “w3”, “4”]
Hide Company Tags Google
Hide Tags Backtracking Bit Manipulation
Hide Similar Problems (M) Subsets (E) Unique Word Abbreviation

My Solution

Accept

class Solution(object):
    def generateAbbreviations(self, word):
        """ :type word: str :rtype: List[str] """

        res = []
        self.helper( 0, word, "", res, 0)
        return res


    def helper(self, index, word, temp_res, res, count):

        if index==len(word):
            if count!=0:
                temp_res = temp_res[0:-count] + str(count)
            res.append( temp_res )
            return

        # append 1
        self.helper( index+1, word, temp_res+'1', res, count+1)

        # append word
        if count!=0:
            temp_res = temp_res[0:-count] + str(count)
        self.helper( index+1, word, temp_res+word[index], res, 0)        

Mistake

1.

if index==len(word)-1

should be

if index==len(word)

Rerun code by myself at the first time.