题目链接

https://leetcode.cn/problems/letter-combinations-of-a-phone-number/

代码

class Solution:def __init__(self):self.letterMap = ["",     # 0"",     # 1"abc",  # 2"def",  # 3"ghi",  # 4"jkl",  # 5"mno",  # 6"pqrs", # 7"tuv",  # 8"wxyz"  # 9]self.result = []self.s = ""def backtracking(self, digits, index):if index == len(digits):self.result.append(self.s)returndigit = int(digits[index])letter = self.letterMap[digit]for i in range(len(letter)):self.s += letter[i]self.backtracking(digits, index + 1)self.s = self.s[:-1]def letterCombinations(self, digits: str) -> List[str]:if len(digits) == 0:return []self.backtracking(digits, 0)return self.result