leetcode

0 class Solution {

1 public:

2 vector<string> letterCombinations(string digits) {

3 vector<string> um = {"abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"}, res = {""};

4

5 for (char d : digits) {

6 vector<string> tmp;

7 for (char l : um[d - '2'])

8 for (const string &s : res)

9 tmp.push_back(s + l);

10 res = tmp;

11 }

12

13 return res.size() > 1 ? res : vector<string>();

14 }

15 };