Java for Leetcode 202 Happy number

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

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

Example:19 is a happy number

12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1
Problem Solving Ideas:

The Hashmap,java is implemented as follows:

    public boolean ishappy (int n) {        hashmap<integer,boolean> hm=new hashmap<integer,boolean> ();        while (!hm.containskey (n) &&n!=1) {        hm.put (n, true);        N=happytime (n);        }        return n==1;    }   static public int HappyTime (int n) {    int res=0;    while (n!=0) {    res+= (n%10) * (N%10);    n/=10;    }    return res;    }

Java for Leetcode 202 Happy number