class Solution(object):
def letterCombinations(self, digits):
"""
:type digits: str
:rtype: List[str]
"""
self.letterMap = [
" ",
"",
"abc",
"def",
"ghi",
"jkl",
"mno",
"pqrs",
"tuv",
"wxyz"
]
self.res = []
if digits == "":
return self.res
self.findCombination(digits,0,"")
return self.res
def findCombination(self,digits,index,s):
if index == len(digits):
self.res.append(s)
return
c = int(digits[index])
letters = self.letterMap[c]
for i in range(len(letters)):
self.findCombination(digits,index+1,s+letters[i])
return
