17. Letter Combinations of a Phone Number
Содержание
Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any order.
A mapping of digits to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.
Example 1:
Input: digits = "23"
Output: ["ad","ae","af","bd","be","bf","cd","ce","cf"]
Example 2:
Input: digits = ""
Output: []
First accepted
class Solution:
def letterCombinations(self, digits: str) -> List[str]:
if not digits:
return []
letters = ['', '', 'abc', 'def',
'ghi', 'jkl', 'mno',
'pqrs', 'tuv', 'wxyz']
result = ['']
for d in digits:
d = int(d)
tmp = []
for letter in letters[d]:
for word in result:
word += letter
tmp.append(word)
result = tmp
return result
