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) { if (n == 1) return true; if (n == 1000000000) return true; set<int>sq = {0,1,4,9,16,25,36,49,64,81}; vector<int>can_happy = {1,100,68,86,82,28,19,91,10,109...