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: #include <bits/stdc++.h>
  int consider(char *s) {
    int len = strlen(s);
    if (len % 2 != 0) return 0;
    int i = 0, j = len / 2;
    while (j < len) {
      if (s[i] != s[j]) return 0;
      i++;
      j++;
    }
    return 1;
  }
  void solution() {
    int times;
    scanf("%d", &times);
    for (int t = 0; t < times; t++) {
      char s[1000];
      scanf("%s", s);
      if (consider(s))
        printf("YES\n");
      else
        printf("NO\n");
    }
  }
  int main() {
    solution();
    return 0;
  }
  