DoublyLinkedList.java

[Vipul Gupta]

In class DoublyLinkedList, the method detachNode(),
Here we need to check the node that we are deleting having prev and next not null as:
case 1 :
if(node.prev!=null){
node.prev.next = node.next;
}else{
dummyHead = node.next; // if the node is head then we need to move the head .
}
case 2 :
if(node.next!=null){
node.next.prev = node.prev;
}else{
dummyTail = node.prev; // if the node is tail then we need to move the tail.
}