# Letter Combinations of a Phone Number – LeetCode Solutions

LeetCode has a Medium coding Problem in Its’ Algorithm Section “Letter Combinations of a Phone Number”. Today We are going to solve this problem in Python. LeetCode Link of the Problem is HERE

#### Question

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 digit to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.

Examples

Input: digits = “23”

Input: digits = “”
Output: []

Input: digits = “2”
Output: [“a”,”b”,”c”]
﻿

Constraints:

• `0 <= digits.length <= 4`
• `digits[i]` is a digit in the range `['2', '9']`.

#### Solution to Letter Combinations of a Phone Number

def create(self,digits, index,m,ans,temp):

if index == len(digits):

return temp

for i in m[digits[index]]:

temp += i

if len(temp) == len(digits):

ans.append(temp)

else:

self.create(digits,index+1,m,ans,temp)

temp = temp[:-1]

return ans

Success

Runtime: 23 ms, faster than 56.19% of Python online submissions.

Memory Usage: 13.3 MB, less than 98.21% of Python online submissions.