description: Petya has an array of integers a_1, a_2, …, a_n. He only likes sorted arrays. Unfortunately, the given array could be arbitrary, so Petya wants to sort it.
  
  Petya likes to challenge himself, so he wants to sort array using only 3-cycles. More formally, in one operation he can pick 3 pairwise distinct indices i, j, and k (1 ≤ i, j, k ≤ n) and apply i → j → k → i cycle to the array a. It simultaneously places a_i on position j, a_j on position k, and a_k on position i, without changing any other element.
  
  For example, if a is [10, 50, 20, 30, 40, 60] and he chooses i = 2, j = 1, k = 5, then the array becomes [\underline{50}, \underline{40}, 20, 30, \underline{10}, 60].
  
  Petya can apply arbitrary number of 3-cycles (possibly, zero). You are to determine if Petya can sort his array a, i. e. make it non-decreasing.
  
  Input
  
  Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 5 ⋅ 10^5). Description of the test cases follows.
  
  The first line of each test case contains a single integer n (1 ≤ n ≤ 5 ⋅ 10^5) — the length of the array a.
  
  The second line of each test case contains n integers a_1, a_2, …, a_n (1 ≤ a_i ≤ n).
  
  It is guaranteed that the sum of n over all test cases does not exceed 5 ⋅ 10^5.
  
  Output
  
  For each test case, print "YES" (without quotes) if Petya can sort the array a using 3-cycles, and "NO" (without quotes) otherwise. You can print each letter in any case (upper or lower).
  
  Example
  
  Input
  
  
  7
  1
  1
  2
  2 2
  2
  2 1
  3
  1 2 3
  3
  2 1 3
  3
  3 1 2
  4
  2 1 4 3
  
  
  Output
  
  
  YES
  YES
  NO
  YES
  NO
  YES
  YES
  
  Note
  
  In the 6-th test case Petya can use the 3-cycle 1 → 3 → 2 → 1 to sort the array.
  
  In the 7-th test case Petya can apply 1 → 3 → 2 → 1 and make a = [1, 4, 2, 3]. Then he can apply 2 → 4 → 3 → 2 and finally sort the array.
solution: import java.util.*;
  
  public class D {
      public static void main(String[] args) {
          Scanner s = new Scanner(System.in);
          int lines = s.nextInt();
  
          s.nextLine();
  
          for (int i = 0; i < lines; i += 1) {
              System.out.println(solve(s.nextInt(), s));
          }
      }
  
  
      public static String solve(int n, Scanner s) {
          int[][] a = new int[n][1];
          for (int i = 0; i < n; i++) {
              a[i] = new int[]{s.nextInt()};
          }
  
          int[][] c = Arrays.copyOf(a, n);
          Arrays.sort(c, new Comparator<int[]>() {
              @Override
              public int compare(int[] o1, int[] o2) {
                  return o1[0] - o2[0];
              }
          });
  
          for (int i = 1; i < n; i++) {
              if (c[i - 1][0] == c[i][0]) return "YES";
          }
  
          for (int i = 0; i < n; i++) {
              c[i][0] = i;
          }
  
          int count = 0;
          int z;
          for (int i = 0; i < n; i++) {
              if (a[i][0] == i) continue;
              count++;
              z = a[i][0];
              a[i][0] = a[z][0];
              a[z][0] = z;
              i--;
          }
  
          return count % 2 == 0 ? "YES" : "NO";
      }
  }
  