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 SquareString {
      public static void main(String[] args) {
          Scanner scanner = new Scanner(System.in);
          int tests = scanner.nextInt();
          String[] answers = new String[tests];
          for (int i = 0; i < tests; i++) {
              String string = scanner.next();
  //            System.out.println(string.length());
              if(string.length()%2 != 0) {
                  answers[i] = "NO";
              } else {
  //                String first = string.substring(0,(string.length()/2)-1);
  //                String second = string.substring(string.length()/2,string.length()-1);
  //                if (first.equals(second)) {
  //                    System.out.println("YES");
  //                } else {
  //                    System.out.println("NO");
  //                }
                  if (solve(string)) {
                      answers[i] = "YES";
                  } else {
                      answers[i] = "NO";
                  }
              }
          }
          for (int i = 0;i < tests; i++) {
              System.out.println(answers[i]);
          }
      }
      private static boolean solve(String string) {
          int pointer = 0;
          for (int j = string.length()/2; j < string.length();j++) {
              if(string.charAt(j) != string.charAt(pointer)) {
                  return false;
              }
              pointer++;
          }
          return true;
      }
  }
  