Singly Linked List Tutorial

Singly Linked List

A Singly Linked List (SLL) is a type of linked list where each node contains a data field and a reference to the next node in the sequence. The last node points to null. It is a dynamic data structure, which means it can grow and shrink during runtime.

Basic Operations on Singly Linked List:

Insertion: Add a node at the beginning, end, or a specific position.
Deletion: Remove a node from the list.
Traversal: Visit all nodes in the list.
Search: Find a node with a specific value.
Reverse: Reverse the order of nodes in the list.

This is the representation of SinglyLinkedList.

A linked list is composed of nodes. Each node contains:

Data: The value stored in the node.
Next Pointer: A reference to the next node in the list.

Insertion: Add a node at the beginning, end, or a specific position.

First we write the Pseudocode for Singly Linked List Operations

Add a node at the beginning.
Adding a node at the end.
Adding a node at a specific position.

Node Structure

Define Node Structure:
    Node:
        - data: Integer
        - next: Node

Adding a node at the end

We add a node at the End of the Singly Linked List.

Pseudocode

java

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Function addNodeAtLast(data: Integer):    Create newNode with given data    If head is null:        head = newNode        tail = newNode    Else:        tail.next = newNode        tail = newNode

Add a node at the beginning

We add a node at the begining of the Singly Linked List.

Pseudocode

java

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Function addNodeAtFirst(data: Integer):    Create newNode with given data    If head is null:        head = newNode    Else:        newNode.next = head        head = newNode

Adding a node at a specific position

We add a node at a specific position of the Singly Linked List.

Pseudocode

java

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Function insertAt(index: Integer, data: Integer):    If index is 0:        Call addNodeAtFirst(data)        Return    If index is less than 0 Or index is greater than the length of linked list:        Print "Invalid index"        Return    Create newNode with given data    Set current to head    Initialize counter j to 0    While j < index - 2:        If current.next is null:            Print "Invalid index"            Return        Set current to current.next        Increment j    Set newNode.next to current.next    Set current.next to newNode

Code for Insertions In Singly Linked List

Code for Insertions In Singly Linked List

Add a node at the beginning.
Adding a node at the end.
Adding a node at a specific position.

Insertions Operations In Singly Linked List

ProgLangCode

java

python

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public class OperationsOnSLL{    private static SLLNode sllNodeHead = null;    private static SLLNode sllNodeTail = null;​    // Node structure    static class SLLNode {        int data;        SLLNode next;​        SLLNode(int data) {            this.data = data;            this.next = null;        }    }​    // Add node at the last of the singly linked list    public static void addNodeAtLast(int data)    {        SLLNode newNode = new SLLNode(data);        if(sllNodeHead == null)        {            sllNodeHead = newNode;            sllNodeTail = newNode;        } else {            sllNodeTail.next = newNode;            sllNodeTail = newNode;        }    }​    // Add node at the first of the singly linked list    public static void addNodeAtFirst(int data)    {        SLLNode newNode = new SLLNode(data);        if(sllNodeHead == null)        {            sllNodeHead = newNode;        } else {            newNode.next = sllNodeHead;            sllNodeHead = newNode;        }    }​    // Insert node at specific index in the singly linked list    public static void insertAt(int index, int data)    {        if(index == 0) {            addNodeAtFirst(data);            return;        }​        if(index < 0) {            System.out.println("Invalid index");            return;        }​        SLLNode newNode = new SLLNode(data);        SLLNode current = sllNodeHead;        int j = 0;        while (j < index - 2) {            current = current.next;            j++;        }        newNode.next = current.next;        current.next = newNode;    }​    // Print singly linked list    public static void printSll(SLLNode sllNodeHead)    {        SLLNode current = sllNodeHead;        while(current != null)        {            System.out.print(current.data + "->");            current = current.next;        }        System.out.print("null");    }​    public static void main(String[] args)    {        OperationsOnSLL.addNodeAtLast(12);        OperationsOnSLL.addNodeAtLast(5);        OperationsOnSLL.addNodeAtFirst(4);        OperationsOnSLL.insertAt(1, 14);        OperationsOnSLL.insertAt(0, 24);​        printSll(sllNodeHead);        System.out.println();    }}

Code Output

24->4->14->12->5->null