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+import java.util.ArrayList;%0A%0A/**%0A * Problem: #217 Contains Duplicate%0A *%0A * Idea:%0A *%0A * Solutions:%0A *  singleNumberHash: using a hash map to store unique characters found.%0A *  singleNumber:%0A *%0A * Note: #canbefaster%0A */%0Apublic class ContainsDuplicate %7B%0A    public boolean containsDuplicate(int%5B%5D nums) %7B%0A        ArrayList%3CInteger%3E list = new ArrayList%3C%3E();%0A        for (int num : nums) %7B%0A            if (list.contains(num)) return true;%0A            list.add(num);%0A        %7D%0A        return false;%0A    %7D%0A%7D%0A

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