// A Java program to find
// if there is a zero sum subarray
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!");
	}
}