Java Linked List Node Deletion At Given Position
Chapter:
Interview Programs
Last Updated:
17-11-2016 14:22:25 UTC
Program:
/* ............... START ............... */
public class JavaNodeDeleteInPosition {
Node head; // head of list
/* Linked list Node */
class Node {
int data;
Node next;
Node(int d) {
data = d;
next = null;
}
}
/* Inserts a new Node at front of the list. */
public void push(int new_data) {
/*
* 1 & 2: Allocate the Node & Put in the data
*/
Node new_node = new Node(new_data);
/* 3. Make next of new Node as head */
new_node.next = head;
/* 4. Move the head to point to new Node */
head = new_node;
}
/*
* Given a reference (pointer to pointer) to the head of a list and a
* position, deletes the node at the given position
*/
void deleteNode(int position) {
// If linked list is empty
if (head == null)
return;
// Store head node
Node temp = head;
// If head needs to be removed
if (position == 0) {
head = temp.next; // Change head
return;
}
// Find previous node of the node to be deleted
for (int i = 0; temp != null && i < position - 1; i++)
temp = temp.next;
// If position is more than number of ndoes
if (temp == null || temp.next == null)
return;
Node next = temp.next.next;
temp.next = next; // Unlink the deleted node from list
}
/*
* This function prints contents of linked list starting from the given node
*/
public void printList() {
Node tnode = head;
while (tnode != null) {
System.out.print(tnode.data + " ");
tnode = tnode.next;
}
}
public static void main(String[] args) {
/* Start with the empty list */
JavaNodeDeleteInPosition llist = new JavaNodeDeleteInPosition();
llist.push(7);
llist.push(1);
llist.push(3);
llist.push(2);
llist.push(8);
System.out.println("\nCreated Linked list is: ");
llist.printList();
llist.deleteNode(4); // Delete node at position 4
System.out.println("\nLinked List after Deletion at position 4: ");
llist.printList();
}
}
/* ............... END ............... */
Output
Created Linked list is:
8 2 3 1 7
Linked List after Deletion at position 4:
8 2 3 1
Notes:
-
If node to be deleted is root, simply delete it. To delete a middle node, we must have pointer to the node previous to the node to be deleted. So if positions is not zero, we run a loop position-1 times and get pointer to the previous node.
Tags
Linked List Node Deletion At Given Position, Java, Interview Programs