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.io.*;
  import java.util.*;
  import java.util.Map.Entry;
  
  public class Div21608B {
  
      static int MOD = 998244353;
  
  	public static void main(String[] args) throws IOException {
  
  		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  		PrintWriter pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
  		
  		int t = Integer.parseInt(br.readLine());		
  	
  	    while(t --> 0){
  	        
  	        int n = Integer.parseInt(br.readLine());
  	        
  	        StringTokenizer st = new StringTokenizer(br.readLine());
  	        
  	        int[] par = new int[n];
  	        ArrayList<Integer> ar = new ArrayList<Integer>();
  	        HashMap<Integer, Integer> rev = new HashMap<Integer, Integer>();
  	        
  	        boolean dg = false;
  	        
  	        for(int i = 0; i < n; i++){
  	            
  	            ar.add(Integer.parseInt(st.nextToken()));
  	            par[i] = ar.get(i);
  	            
  	            if(!rev.containsKey(par[i]))
  	                rev.put(par[i], i);
  	            else
  	                dg = true;
  	            
  	        }
  	        
  	        Collections.sort(ar);
  	        
  	        boolean[] vis = new boolean[n];
  	        int even = 0;
  	        
  	        for(int i = 0; i < n; i++){
  	            
  	            if(vis[i] || rev.get(ar.get(i)) == i)
  	                continue;
  	                
  	            int size = 0;
  	            int j = i;
  	            
  	            while(!vis[j]){
  	                
  	                vis[j] = true;
  	                size++;
  	                
  	                j = rev.get(ar.get(j));
  	                
  	            }
  	            
  	            if(size % 2 == 0)
  	                even++;
  	            
  	        }
  	        
  	        if(even % 2 == 0 || dg)
  	            pw.println("YES");
  	        else
  	            pw.println("NO");
  	            
  	    }
  	    
  	    pw.close();
  
  	}
  	
  }