@@ -0,0 +1,629 @@
+package leetcode;%0A%0Aimport java.util.HashSet;%0Aimport java.util.Set;%0A%0Apublic class Task136 %7B%0A%0A    public static void main(String%5B%5D args) %7B%0A        System.out.println(new Task136().singleNumber(new int%5B%5D%7B2, 2, 1%7D));%0A        System.out.println(new Task136().singleNumber(new int%5B%5D%7B4, 1, 2, 1, 2%7D));%0A        System.out.println(new Task136().singleNumber(new int%5B%5D%7B1%7D));%0A    %7D%0A%0A    public int singleNumber(int%5B%5D nums) %7B%0A        Set%3CInteger%3E seen = new HashSet%3C%3E();%0A        for (int num : nums) %7B%0A            if (!seen.remove(num)) %7B%0A                seen.add(num);%0A            %7D%0A        %7D%0A        return seen.iterator().next();%0A    %7D%0A%7D%0A

Add Task136