Happy Number

Any number will be called a happy number if, after repeatedly replacing it with a number equal to the sum of the square of all of its digits, leads us to the number 1. All other (not-happy) numbers will never reach 1. Instead, they will be stuck in a cycle of numbers that does not include 1.

Given a positive number n, return true if it is a happy number otherwise return false.

Example 1:

• Input: 23
• Output: true

class Solution {
    public boolean isHappy(int n) {
        var slow = n;
        var fast = n;
        while (slow != 1 && fast != 1) {
            slow = findSquare(slow);
            fast = findSquare(findSquare(fast));
            if (slow != 1 && fast != 1 && fast == slow) {
                return false;
            }
        }
        return true;
    }

    int findSquare(int n) {
        var square = 0;
        while (n > 0) {
            var rem = n % 10;
            n = n / 10;
            square += rem * rem;
        }
        return square;
    }

}