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, 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.

Example: 19 is a happy number

• 12 + 92 = 82
• 82 + 22 = 68
• 62 + 82 = 100
• 12 + 02 + 02 = 1

 1 public class Solution {
 2     public boolean isHappy(int n) {
 3         int m = 0;
 4
 5         while (n > 9)
 6         {
 7             m += Math.pow( n%10,2 );
 8             n = n / 10;
 9         }
10         m += Math.pow( n,2 );
11
12         if(m > 9)
13         {
14             return isHappy(m);
15         }
16
17         if(m == 1)
18         {
19             return true;
20         }else{
21             return false;
22         }
23     }
24 }