题目:
给定一个仅包含数字 2-9
的字符串,返回所有它能表示的字母组合。
给出数字到字母的映射如下(与电话按键相同)。注意 1 不对应任何字母。
示例:
输入:"23" 输出:["ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf"].
说明:
尽管上面的答案是按字典序排列的,但是你可以任意选择答案输出的顺序。
题目链接:https://leetcode-cn.com/problems/letter-combinations-of-a-phone-number/description/
答案:
class Solution(object):
def letterCombinations(self, digits):
"""
:type digits: str
:rtype: List[str]
"""
self.ma = {'2':'abc','3':'def','4':'ghi','5':'jkl','6':'mno','7':'pqrs','8':'tuv','9':'wxyz'}
if not digits:
return []
res = [ i for i in self.ma[digits[0]]]
for i in digits[1:]:
res = [ m+n for m in res for n in self.ma[i] ]
return res