Not able to submit the working code

this is my code and i am unable to submit it

import java.util.*;

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

    int n=in.nextInt();
    int arr[]=new int[n];

    for(int i=0;i<n;i++)
    {
        arr[i]=in.nextInt();
    }

    qs(arr,0,n-1);


}

    public static void swap (int arr[], int x, int y)
{
    int temp = arr[x];
    arr[x] = arr[y];
    arr[y] = temp;
}

public static void qs(int[] arr, int l, int h) 
{
   
    if (arr == null || arr.length == 0){
        
        return;
    }
     
    if (l>= h){
     
        return;
    }

    
    int mid = l + (h - l) / 2;
    int pivot = arr[mid];

    
    int i = l, j = h;
    while (i <= j) 
    {
    
        while (arr[i] < pivot) 
        {
            i++;
        }
    
        while (arr[j] > pivot) 
        {
            j--;
        }
        if (i <= j) 
        {
            swap (arr, i, j);
            i++;
            j--;
        }
    }
    if (l < j){
        qs(arr, l, j);
    }
    if (h > i){
        qs(arr, i, h);
    }

    if(l==0 && h==arr.length-1)
    {
         display(arr);
    }

     
   
}

public static void display(int arr[])

{
for(int i=0;i<arr.length;i++)
{
System.out.print(arr[i]+" ");
}
}

}