Help me in solving AOJ221 problem

help
,
1

My issue

complex problem even when output correct ; showing its wrong

My code

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner read = new Scanner(System.in);
        int t = read.nextInt();

        for (int i = 0; i < t; i++) {
            int n = read.nextInt();
            int[] a = new int[2 * n];

            // Read the array elements
            for (int j = 0; j < 2 * n; j++) {
                a[j] = read.nextInt();
            }

            // Update your code below this line
            System.out.println(validPrices(n, a) ? "Yes" : "No");
        }
    }

    // Function to check if the prices are valid
    static boolean validPrices(int n, int[] arr) {
        Set<Integer> set = new HashSet<>();

        for (int value : arr) {
            if (set.contains(value)) {
                return false;
            } else {
                set.add(value);
            }
        }

        return true;
    }
}

Learning course: Placement preparation using Java
Problem Link: Review problem - 4 Practice Problem in Placement preparation using Java - CodeChef