leetcode

0 class Solution {

1 public:

2 vector<string> validStrings(int n) {

3 vector<string> res = {"0", "1"};

4

5 for (int i = 1; i < n; i++) {

6 for (int j = size(res) - 1; j >= 0; j--) {

7 if (res[j].back() == '1') res.push_back(res[j] + '0');

8 res[j] += '1';

9 }

10 }

11

12 return res;

13 }

14 };