@@ -0,0 +1,400 @@
+class Solution %7B%0A    public int singleNumber(int%5B%5D nums) %7B%0A        int single = 0;%0A        for (int i=0; i%3Cnums.length; i++) %7B%0A            single %5E= nums%5Bi%5D;%0A        %7D%0A        return single;%0A    %7D%0A%7D%0A%0Apublic class single_number %7B%0A    public static void main(String%5B%5D args) %7B%0A        Solution s = new Solution();%0A        int%5B%5D a = %7B1,2,3,4,3,2,1%7D;%0A        System.out.println(s.singleNumber(a));%0A    %7D%0A%7D

add https://leetcode.com/problems/single-number/