#include "leetcode.h" class Solution { public: bool isHappy(int n) { int slow, fast; slow = fast = n; do { slow = square(slow); for (int i = 0; i < 2; i++) fast = square(fast); } while (slow != fast); if (slow == 1) return 1; else return 0; } private: int square(int n) { int num = 0, tmp; while (n) { tmp = n % 10; num += tmp * tmp; n /= 10; } return num; } }; int main() { Solution obj; if (obj.isHappy(19)) cout << "true"; else cout << "false"; }