2443. Sum of Number and Its Reverse ¶ Time: $O(\texttt{num})$ Space: $O(1)$ C++ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19class Solution { public: bool sumOfNumberAndReverse(int num) { for (int i = num / 2; i <= num; ++i) if (num == i + reversed(i)) return true; return false; } private: int reversed(int num) { int ans = 0; while (num > 0) { ans = ans * 10 + num % 10; num /= 10; } return ans; } };