package datastructure.hashtable; import java.util.HashMap; /** * The type Sub array zero. */ public class SubArrayZero { /** * Find sub zero boolean. * * @param arr the arr * @return the boolean */ public static boolean findSubZero(int[] arr) { //Use HashMap to store Sum as key and index i as value till sum has been calculated. //Traverse the array and return true if either //arr[i] == 0 or sum == 0 or HashMap already contains the sum //If you completely traverse the array and havent found any of the above three //conditions then simply return false. HashMap hMap = new HashMap<>(); int sum = 0; // Traverse through the given array for (int i = 0; i < arr.length; i++) { sum += arr[i]; if (arr[i] == 0 || sum == 0 || hMap.get(sum) != null) return true; hMap.put(sum, i); } return false; } /** * Main. * * @param args the args */ public static void main(String args[]) { int[] arr = {6, 4, 19, -2, 2, 12, 9}; System.out.println(findSubZero(arr)); } }