LintCode-488.快乐数

1^2 + 9^2 = 82
8^2 + 2^2 = 68
6^2 + 8^2 = 100
1^2 + 0^2 + 0^2 = 1

public class Solution {
    /**
     * @param n an integer
     * @return true if this is a happy number or false
     */
    public boolean isHappy(int n) {
        // Write your code here
        Set<Integer> set = new HashSet<>();
        int temp = 0;
        Integer nn = new Integer(n);
        while(nn != 1){
            if(set.contains(nn)) return false;
            set.add(nn);
            temp = nn;
            nn = 0;
            while(temp != 0){
                nn += (temp%10)*(temp%10);
                temp = temp / 10;
            }
        }
        return true;
    }
}