leetcode

0 class Solution {

1 public:

2 string digitSum(string s, int k) {

3 while (s.size() > k) {

4 string tmp = "";

5 for (int i = 0; i < s.size();) {

6 int sum = 0;

7 for (int j = 0; j < k && i < s.size(); i++, j++)

8 sum += s[i] - '0';

9 tmp += to_string(sum);

10 }

11 s = tmp;

12 }

13 return s;

14 }

15 };