leetcode

0 class Solution {

1 public:

2 bool canPartition(const string &s, const int target) {

3 if (s == "" && target == 0) return true;

4 if (target < 0) return false;

5

6 int left = 0;

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

8 left = left * 10 + s[i] - '0';

9 if (canPartition(s.substr(i + 1), target - left)) return true;

10 }

11 return false;

12 }

13

14 int punishmentNumber(int n) {

15 int res = 0;

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

17 const int sqr = i * i;

18 if (canPartition(to_string(sqr), i)) res += sqr;

19 }

20 return res;

21 }

22 };