class Solution {
public:
    int sumDigitSquare(int n)
    {
        int ans = 0;
        while (n) {
            int digit = n % 10;
            ans += digit * digit;
            n /= 10;
        }
    return ans;
    }

    bool isHappy(int n)
{
while (1) {

if (n == 1)
return true;

// Replace n with sum of squares
// of digits
n = sumDigitSquare(n);

// Number is not Happy if we reach 4
if (n == 4)
return false;
}

return false;
}

};