LeeCode-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 bool isHappy(int n)
 2 {
 3         if(n<0)
 4         return false;
 5
 6     do
 7     {
 8         int sum=0;
 9         while(n!=0)
10         {
11             sum=sum+(n%10)*(n%10);
12             n=n/10;
13         }
14
15         n=sum;
16
17         if(n==89)
18         {
19             return false;
20         }
21
22
23
24         if(n==1)
25         {
26             return true;
27         }
28     }
29     while (true);
30 }