#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;
    }
};