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

class Solution {
public:
bool isHappy(int n) {
if(n<=0){
return false;
}
unordered_set<int> uset;
int squareSum = 0;
while(squareSum!=1){
squareSum = 0;
while(n){
squareSum += (n%10)*(n%10);
n /= 10;
}
n = squareSum ;
if(uset.find(n)!=uset.end()){
return false;
}
uset.insert(n);
}
return true;
}
};