leetcode

0 class Solution {

1 vector<string> res;

2

3 void rec(string &s, int st, string crnt) {

4 while (st < s.size() && !isalpha(s[st]))

5 crnt += s[st++];

6 if (st == s.size()) {

7 res.push_back(crnt);

8 return;

9 }

10

11 char c = tolower(s[st]);

12 rec(s, st + 1, crnt + c);

13 rec(s, st + 1, crnt + (char)toupper(c));

14 }

15

16 public:

17 vector<string> letterCasePermutation(string s) {

18 rec(s, 0, "");

19 return res;

20 }

21 };