LC 0320 [M] Generalized Abbreviation - ALawliet/algorithms GitHub Wiki

class Solution:
    def generateAbbreviations(self, word: str) -> List[str]:
      def abbreviate(path):
        res = ''
        
        count = 0
        for x in path:
          if x == '_':
            count += 1
          elif x.isalpha(): # abbreviation _ and letter cannot be adjacent so if else works
            if count:
              res += str(count)
              count = 0
            res += x
            
        # one more for last char is count with no letters remaining
        if count:
          res += str(count)
        
        return res

      def dfs(i, path):
        if i == len(word):
          res.append(abbreviate(path))
        else:
            dfs(i + 1, path + word[i])
            dfs(i + 1, path + '_')

      res = []
      dfs(0, '')
      return res

class Solution(object):
    def generateAbbreviations(self, word):
        def helper(idx, soFar, count):
            if idx == len(word):
                # Once we reach the end, append current to the result
                coll.append(soFar + (str(count) if count > 0 else soFar))
            else:
                # Skip current position, and increment count
                helper(idx + 1, soFar, count + 1)
                # Include current position, and zero-out count
                helper(idx + 1, soFar + (str(count) if count > 0 else '') + word[idx], 0)

        coll = []
        helper(0, '', 0)
        return coll

class Solution:
    def generateAbbreviations(self, word: str) -> List[str]:
      def abbreviate(soFar):
        res = ''
        count = 0
        for i in soFar:
          if i == '_':
            count += 1
          else:
            if count > 0:
              res += str(count)
              count = 0
            res += i
        if count:
          res += str(count)
        return res

      def helper(idx, soFar):
        if idx == len(word):
          coll.append(abbreviate(soFar))
          return

        helper(idx + 1, soFar + word[idx])
        helper(idx + 1, soFar + '_')

      coll = []
      helper(0, '')
      return coll