Insert a Node at a Specific Position in a Linked List
A new element is inserted at the given specified position in the singly linked list. For example - if the given List is 10->7->20->5 and a new value 8 is added at position 3, the Linked List becomes 10->7->8->20->5.
Example: Insert a Node Position :3 and value: 8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65 | /*Node of a single linked list of integer */
public class SinglyLinkedList {
private static Node head; /* instance variable */
private static class Node {
private int data; /* we assume data integer */
private Node next; /* Create a node with the given data and next node */
public Node(int data) {
this.data = data;
this.next = null;
}
}
/* Display single list */
public void display() {
Node current = head;
while (current != null) {
System.out.print(current.data + " --> ");
current = current.next;
}
System.out.println("null");
}
public void insert(int position, int value) {
Node newnode = new Node(value);
if(position ==1) {
newnode.next = head;
head = newnode;
}else {
Node previous = head;
int count = 1;
while(count< position - 1 ) {
previous = previous.next;
count++;
}
Node current = previous.next;
previous.next = newnode;
newnode.next = current;
}
}
public static void main(String[] args) {
SinglyLinkedList s = new SinglyLinkedList();
s.head = new Node(10);
Node second = new Node(7);
Node third = new Node(20);
Node fourth = new Node(5);
s.head.next = second; // 10 --> 7
second.next = third; // 10 -->7 -->20
third.next = fourth; // 10 -->7 -> 20 -->5 -->null
System.out.println("Before Singly linked list:");
s.display();
System.out.println("Linked list after insertion at position 3 and value 8:");
s.insert(3, 8);
s.display();
}
}
|
Output:
Before Singly linked list:
10 --> 7 --> 20 --> 5 --> null
Linked list after insertion at position 3 and value 8:
10 --> 7 --> 8 --> 20 --> 5 --> null
