ZeroSumSubArray, Java

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//'main' method must be in a class 'Rextester'.
//Compiler version 1.8.0_72

import java.util.*;
import java.lang.*;

class Rextester
{  
    private static final int[] EMPTY = {};
    // Returns int[] if arr[] has a subarray with sero sum
    static int[] findZeroSumSubarray(int arr[])
    {
        if (arr.length == 0) return EMPTY;
        // Creates an empty hashMap hM
        HashMap<Integer, Integer> hM = new HashMap<Integer, Integer>();
        // Initialize sum of elements
        int sum = 0;        
        for (int i = 0; i < arr.length; i++)
        {   
            sum += arr[i]; 
            if (arr[i] == 0)   //Current element is 0
            {
               return new int[]{0}; 
            }
            else if (sum == 0)  // sum of elements from 0 to i is 0
            {
                return Arrays.copyOfRange(arr, 0, i+1);
            }
            else if (hM.get(sum) != null) // sum is already present in hash map
            {
                return Arrays.copyOfRange(arr, hM.get(sum)+1, i+1);
            }
            else
            {
                // Add sum to hash map
                hM.put(sum, i);
            }
        }    
        // We reach here only when there is no subarray with 0 sum
        return null;
    }        
     
    public static void main(String arg[])
    {
        //int arr[] = {};
        int arr[] = { 2, -3, 1, 4, 6}; //Case left
        //int arr[] = { 0, 2, -3, 1, 4, 6}; //Case 0
        //int arr[] = { 4, 2, -3, 1, 4}; // Case middle
        int result[] = findZeroSumSubarray(arr);
        if (result == EMPTY){
            System.out.println("An empty array is ZeroSum, LOL"); 
        }
        else if ( result != null){
            System.out.println("Found a subarray with 0 sum :" );
            for (int i: result) System.out.println(i);
        }
        else
            System.out.println("No Subarray with 0 sum");            
    }           
}

[ + ] Show input
Compilation time: 0.62 sec, absolute running time: 0.13 sec, cpu time: 0.06 sec, memory peak: 19 Mb, absolute service time: 0,76 sec