Subarray with 0 sum Java

PROGRAM TO FIND IF THERE IS A SUBARRAY WITH SUM 0




import java.util.HashSet;

import java.util.Set;

 

class ZeroSumSubarray

{

    // Returns true if arr[]

    // has a subarray with sero sum

    static Boolean subArrayExists(int arr[])

    {

        // Creates an empty hashset hs

        Set<Integer> hs = new HashSet<Integer>();

 

        // Initialize sum of elements

        int sum = 0;

 

        // Traverse through the given array

        for (int i = 0; i < arr.length; i++)

        {

            // Add current element to sum

            sum += arr[i];

 

            // Return true in following cases

            // a) Current element is 0

            // b) sum of elements from 0 to i is 0

            // c) sum is already present in hash map

            if (arr[i] == 0

                || sum == 0

                || hs.contains(sum))

                return true;

 

            // Add sum to hash set

            hs.add(sum);

        }

 

        // We reach here only when there is

        // no subarray with 0 sum

        return false;

    }

 

    // Driver code

    public static void main(String arg[])

    {

        int arr[] = { -3, 2, 3, 1, 6 };

        if (subArrayExists(arr))

            System.out.println(

                "Found a subarray with 0 sum");

        else

            System.out.println("No Such Sub Array Exists!");

    }

}




OUTPUT:

No Such Sub Array Exists!

CREDITS: https://www.geeksforgeeks.org/find-if-there-is-a-subarray-with-0-sum/