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+/**%0A *Given an array of integers, every element appears twice except for one. Find that single one.%0A *%0A *Note:%0A *Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?%0A */%0Aclass Solution %7B%0A    public int singleNumber(int%5B%5D nums) %7B%0A        Map%3CInteger, Integer%3E map = new HashMap%3C%3E();%0A        for (int num : nums) %7B%0A            if (map.containsKey(num)) %7B%0A                map.put(num, map.get(num) + 1);%0A            %7D else %7B%0A                 map.put(num, 1);%0A            %7D%0A        %7D%0A        %0A        Iterator it = map.entrySet().iterator();%0A        while (it.hasNext()) %7B%0A            Map.Entry entry = (Map.Entry) it.next();%0A            if ((Integer) entry.getValue() == 1) return (Integer) entry.getKey();%0A        %7D%0A        %0A        return 0;%0A    %7D%0A%7D%0A

Create SingleNumber.java