├── Java Regex
└── Java Regex2


/Java Regex:
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 1 | import java.util.Scanner;
 2 | import java.util.regex.Matcher;
 3 | import java.util.regex.Pattern;
 4 | class Solution{
 5 |     public static void main(String[] args){
 6 |         Scanner in = new Scanner(System.in);
 7 |         while(in.hasNext()){
 8 |             String IP = in.next();
 9 |             System.out.println(IP.matches(new MyRegex().pattern));
10 |         }
11 |     }
12 | }
13 | class MyRegex{
14 |     String num = "([01]?\\d{1,2}|2[0-4]\\d|25[0-5])";
15 |     String pattern = num + "." +  num + "." +  num + "." + num;
16 | }
17 | 


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/Java Regex2:
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 1 | import java.util.Scanner;
 2 | import java.util.regex.Matcher;
 3 | import java.util.regex.Pattern;
 4 | public class DuplicateWords {
 5 |     public static void main(String[] args) {
 6 |         String regex = "\\b(\\w+)(?:\\W+\\1\\b)+";
 7 |         Pattern p = Pattern.compile(regex, Pattern.CASE_INSENSITIVE);
 8 |         Scanner in = new Scanner(System.in);
 9 |         int numSentences = Integer.parseInt(in.nextLine());
10 |         while (numSentences-- > 0) {
11 |             String input = in.nextLine();
12 |             Matcher m = p.matcher(input);
13 |             while (m.find()) {
14 |                 input = input.replaceAll(m.group(), m.group(1));
15 |             }
16 |             System.out.println(input);
17 |         }
18 |         in.close();
19 |     }
20 | }
21 | 


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