From b6581eaa168765590ec173f3b2f27a0c6558ccbb Mon Sep 17 00:00:00 2001
From: Abhijay Kumar <abhijaynsit@gmail.com>
Date: Thu, 30 May 2019 13:04:15 +0530
Subject: [PATCH] Fix for Issue #773. Deleting an element that doesn't exist
 causes NPE

---
 DataStructures/Lists/DoublyLinkedList.java | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/DataStructures/Lists/DoublyLinkedList.java b/DataStructures/Lists/DoublyLinkedList.java
index fd250d956..677487e1d 100644
--- a/DataStructures/Lists/DoublyLinkedList.java
+++ b/DataStructures/Lists/DoublyLinkedList.java
@@ -116,8 +116,13 @@ public class DoublyLinkedList {
     public void delete(int x) {
         Link current = head;
 
-        while (current.value != x) // Find the position to delete
-            current = current.next;
+        while (current.value != x) {// Find the position to delete
+            if (current != tail) {
+                current = current.next;
+            } else {// If we reach the tail and the element is still not found
+                throw new RuntimeException("The element to be deleted does not exist!");
+            }
+        }
 
         if (current == head)
             deleteHead();