description: A string is called square if it is some string written twice in a row. For example, the strings "aa", "abcabc", "abab" and "baabaa" are square. But the strings "aaa", "abaaab" and "abcdabc" are not square.
  
  For a given string s determine if it is square.
  
  Input
  
  The first line of input data contains an integer t (1 ≤ t ≤ 100) —the number of test cases.
  
  This is followed by t lines, each containing a description of one test case. The given strings consist only of lowercase Latin letters and have lengths between 1 and 100 inclusive.
  
  Output
  
  For each test case, output on a separate line:
  
    * YES if the string in the corresponding test case is square, 
    * NO otherwise. 
  
  
  
  You can output YES and NO in any case (for example, strings yEs, yes, Yes and YES will be recognized as a positive response).
  
  Example
  
  Input
  
  
  10
  a
  aa
  aaa
  aaaa
  abab
  abcabc
  abacaba
  xxyy
  xyyx
  xyxy
  
  
  Output
  
  
  NO
  YES
  NO
  YES
  YES
  YES
  NO
  NO
  NO
  YES
solution: import java.util.Scanner;
  
  public class test {
    public static void main(String[] args) {
      Scanner reader = new Scanner(System.in);
      int numberOfCases= reader.nextInt();
      reader.nextLine();
      String[] testCases= new String[numberOfCases];
      String[] results=new String[numberOfCases];
      for(int i=0;i<numberOfCases;i++){
        String testCase= reader.nextLine();
        results[i]=isSquare(testCase);
      }
      for (String result:results
           ) {
        System.out.println( result);
      }
  
    }
  
    private static String isSquare(String testCase) {
      if (testCase.length()%2==1) {
          return "NO";
      }
      if(testCase.substring(0,testCase.length()/2).equals(testCase.substring(testCase.length()/2)))
      return "YES";
      return "NO";
    }
  
  }
  