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

bool isHappy(int n)
{
        if(n<0)
        return false;
    
    do 
    {
        int sum=0;
        while(n!=0)
        {
            sum=sum+(n%10)*(n%10);
            n=n/10;
        }
        
        n=sum;

        if(n==89)
        {
            return false;
        }

    

        if(n==1)
        {
            return true;
        }
    } 
    while (true);
}