Algorithms —check Happy Number

Is this Happy Number?

Happy Number

What is Happy Number? Please refer wiki

Brief: 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.

Solution 1:

class Solution {
public:
    bool isHappy(int n) {
        int originN = n;
        if (originN == 1)
            return true;
        else if (originN == 4)
            return false;
        int newN = 0;
        while (originN > 0) {
            newN += (originN % 10) * (originN % 10);
            originN /= 10;
        }
        return isHappy(newN);
    }
};

Solution 2:

class Solution {
public:
    bool isHappyNumber(int n) {
        if (n == 1) return true;
        else if (n == 4) return false;
        int digit = 0;
        int sum = 0;
        while (n > 0) {
            digit = n % 10;
            sum += (digit * digit);
            n /= 10;
        }
        return isHappyNumber(sum);
    }
};

You can use this tool for test: http://calculatorschool.com

Have fun!