@@ -0,0 +1,493 @@
+/**%0A * Problem: https://leetcode.com/problems/happy-number/%0A */%0A%0Apublic class Solution %7B%0A    public boolean isHappy(int n) %7B%0A        return isHappy(n, new HashSet%3CInteger%3E());%0A    %7D%0A    %0A    private boolean isHappy(int n, HashSet%3CInteger%3E set) %7B%0A        if(set.contains(n)) return false;%0A        if(n == 1) return true;%0A        set.add(n);%0A        int sum = 0;%0A        while(n %3E 0) %7B%0A            sum += (n%2510) * (n%2510);%0A            n /= 10;%0A        %7D%0A        return isHappy(sum, set);%0A    %7D%0A%7D%0A

Create Happy_Number.java