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+package leetcode.happy_number;%0A%0Aimport java.util.HashSet;%0Aimport java.util.Set;%0A%0Apublic class Solution %7B%0A    public boolean isHappy(int n) %7B%0A        if(n %3C= 0) return false;%0A        Set%3CInteger%3E appeared = new HashSet%3CInteger%3E();%0A        while(!appeared.contains(n))%7B%0A            appeared.add(n);%0A            int s = 0;%0A            while(n %3E 0)%7B%0A                s += (n %25 10) * (n %25 10);%0A                n /= 10;%0A            %7D%0A            n = s;%0A        %7D%0A        return n == 1;%0A    %7D%0A%7D

Add java solution for 202. Happy Number