#include <unordered_set> class Solution { public: /** * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 * * * @param n int整型 * @return bool布尔型 */ bool happynum(int n) { unordered_set<int> seen; while (n != 1 && seen.find(n) == seen.end()) { seen.insert(n); n = getNext(n); } return n == 1; } private: int getNext(int n) { int sum = 0; while (n > 0) { int digit = n % 10; sum += digit * digit; n /= 10; } return sum; } };