Happy Number

Write an algorithm to determine if a number n is "happy".

A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.

Return True if n is a happy number, and False if not.

Input: 19
Output: true
Explanation: 
12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1

Solution:

class Solution {
    public boolean isHappy(int n) {
        Set<Integer> states = new HashSet<>();
        while (states.add(n)) {
            if (n == 1) {
                return true;
            }
            int next = 0;
            while (n > 0) {
                int v = n % 10;
                next += v * v;
                n /= 10;
            }
            n = next;
        }
        return false;
    }
}