Singly Linked List in C (All Methods)

September 17, 2025

Singly Linked List in C

Singly Linked List in C is one of the simplest linear data structures, that we use for storing our data in an easy and efficient way. Linked List in C comprises nodes like structures, which can further be divided into 2 parts in the case of a singly linked list. These two parts are-:

Node – for storing the data.
Pointer – for storing the address of the next node

Note In a Singly linked list there is only one pointer type variable, that contains the address of the next node.

Singly Linked List Program in Data Structure Implementation

We implement Linked List using user-defined data type, with the help of structure or struct.

Since the Singly linked list has only 1 pointer type value, which means it can store the address of only one node, which will be the next to it.

More about it As a result, we can only move in one direction in a Singly Linked List i.e. from head to tail, which makes traversing a linked list more difficult. Implementing linked list rather than using array is better, since the insertion and deletion operations in Linked List are less complicated and less time consuming in comparison with arrays.

How to Construct a Singly Linked List in C ?

For constructing a singly linked list in C we make use of the structure keyword(struct), for creating user-defined data types, which can store various different types of data in the nodes of the singly linked list.

Each linked list has two parts –

One for storing the desired data
The other is a pointer type variable, which stores the address of the next node.

The syntax for creating a node

struct Node
{
  int Data;
  Struct Node *next;
};

This code will create a data type Node, which will be able to store two values-:

int value – data
pointer value – address of the next node

Introduction to Linked List

Singly Linked List

Insertion in singly Linked List

Deletion in singly Linked List

Reverse a linked list

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Insertion of a node

void insertStart (struct Node **head, int data)
{

  struct Node *newNode = (struct Node *) malloc (sizeof (struct Node));

  newNode - >
  data = data;
  newNode - >
  next = *head;

  //changing the new head to this freshly entered node
  *head = newNode;
}

Deletion of a node

void deleteStart(struct Node **head)
{
  struct Node *temp = *head;

  // if there are no nodes in Linked List can't delete
  if (*head == NULL)
    {
      printf ("Linked List Empty, nothing to delete");
      return;
    }

  // move head to next node
  *head = (*head)->next;

  free (temp);
}

Traversal in a Singly Linked List

void display(struct Node* node)
{
    printf("Linked List: ");
    
    // as linked list will end when Node is Null
    while(node!=NULL){
        printf("%d ",node->data);
        node = node->next;
    }
    
    printf("\n");
}

Code for Implementing Single Linked List in C

Run

#include<stdio.h>
#include<stdlib.h>

struct Node
{
  int data;
  struct Node *next;
};

void deleteStart (struct Node **head)
{
  struct Node *temp = *head;

  // if there are no nodes in Linked List can't delete
  if (*head == NULL)
    {
      printf ("Linked List Empty, nothing to delete");
      return;
    }

  // move head to next node
  *head = (*head)->next;

  printf ("\n%d deleted\n", temp->data);
  free (temp);
}

void insertStart (struct Node **head, int data)
{

  // dynamically create memory for this newNode
  struct Node *newNode = (struct Node *) malloc (sizeof (struct Node));

  // assign data value
  newNode->data = data;
  // change the next node of this newNode 
  // to current head of Linked List
  newNode->next = *head;

  //re-assign head to this newNode
  *head = newNode;
  printf ("\n%d Inserted\n", newNode->data);
}

void display (struct Node *node)
{
  printf ("\nLinked List: ");

  // as linked list will end when Node is Null
  while (node != NULL)
    {
      printf ("%d ", node->data);
      node = node->next;
    }
  printf ("\n");
}

int main ()
{
  struct Node *head = NULL;

  // Need '&' i.e. address as we need to change head
  insertStart (&head, 100);
  insertStart (&head, 80);
  insertStart (&head, 60);
  insertStart (&head, 40);
  insertStart (&head, 20);

  // No Need for '&' as not changing head in display operation
  display (head);

  deleteStart (&head);
  deleteStart (&head);
  display (head);

  return 0;
}

Output

100 Inserted

80 Inserted

60 Inserted

40 Inserted

20 Inserted

Linked List: 20 40 60 80 100 

20 deleted

40 deleted

Linked List: 60 80 100

Time Complexity
For Singly Linked List

Best

O(1)

Average

O(n)

Worst

O(n)

Average Comparisons

(n+1)/2

Time Complexity
For Singly Linked List

Best

O(1)

Average

O(n)

Worst

O(n)

Average Comparisons

(n+1)/2

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Singly Linked List in C (All Methods)