JavaRegex2-DuplicateWords.java

    import java.util.Scanner;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;

    public class DuplicateWords
    {
        public static void main(String[] args){

            String pattern = "\\b(\\w+)(\\b\\W+\\b\\1\\b)*";
            Pattern r = Pattern.compile(pattern, Pattern.MULTILINE+Pattern.CASE_INSENSITIVE);

            Scanner in = new Scanner(System.in);
            int testCases = Integer.parseInt(in.nextLine());
            while(testCases>0){
                String input = in.nextLine();
                Matcher m = r.matcher(input);
                boolean findMatch = true;
                while(m.find( )){
                    input = input.replaceAll(m.group(),m.group(1));
                    findMatch = false;
                }
                System.out.println(input);
                testCases--;
            }
        }
    }