C Program to search an element in a linked list

March 20, 2025

To find an element in a linked list

C Program to search an element in a linked list. In this article, we will find an element just like we find an element in an array which is the most common operation performed on any data structure.

For Example:-

  • Input: 5 -> 6 -> 9 -> 3 -> 47
  • Search Item: 9
  • Output: Element found position 3
list

Methods Discussed

We will discuss two methods in this post –

  • Method 1: Iterative
  • Method 2: Recursive

Structure for creating node in the linked list as follows:-

struct node 
{ 
    int data; // Data 
    struct node *next; // For address of next node
};

Implementation for C Program to search an element in a linked list:-

  • Initialize head = Null
  • Add a few items to the Linked List
  • Take input from the user for the item he wants to search
  • Linearly traverse the Linked List from head to the end until you hit the null node
  • For each node check if its data value == item user wants to search
  • Return index of node where data was found else return -1
C Program to search an element in a linked list

Insertion in a Sorted Linked List

Delete alternate nodes of a Linked List

Find middle of the linked list

Reverse a linked list in groups of given size

Find kth node from end of the linked list

 

 

Method 1 (Iterative)

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

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

void display (struct Node *node)
{

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

int searchElement (struct Node *head, int item)
{
  struct Node *current = head;	// Initialize current
  int index = 0;
  // traverse till then end of the linked list
  while (current != NULL)
    {
      if (current->data == item)
	{
	  return index;
	}
      current = current->next;
      index++;
    }
  return -1;
}

int main ()
{
  int item;

  //creating 4 pointers of type struct Node
  //So these can point to address of struct type variable
  struct Node *head = NULL;
  struct Node *node2 = NULL;
  struct Node *node3 = NULL;
  struct Node *node4 = NULL;

  // allocate 3 nodes in the heap 
  head = (struct Node *) malloc (sizeof (struct Node));
  node2 = (struct Node *) malloc (sizeof (struct Node));
  node3 = (struct Node *) malloc (sizeof (struct Node));
  node4 = (struct Node *) malloc (sizeof (struct Node));


  head->data = 10;		// data set for head node 
  head->next = node2;		// next pointer assigned to address of node2 

  node2->data = 15;
  node2->next = node3;

  node3->data = 20;
  node3->next = node4;

  node4->data = 25;
  node4->next = NULL;

  printf ("Linked List: ");
  display (head);

  printf ("Enter element to search: ");
  scanf ("%d", &item);

  int index = searchElement (head, item);

  if (index == -1)
    printf ("Item not found");
  else
    printf ("Item found at position: %d", index + 1);

  return 0;
}

Output

Linked List: 10 15 20 25 
Enter element to search: 20
Item found at position: 3

Method 2 (Recursive)

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

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

void display (struct Node *node)
{

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

int searchElement (struct Node *head, int item, int index)
{
  // Base case
  if (head == NULL)
    return -1;

  // If data is present in current node, return true
  if (head->data == item)
    return index;

  // not present here will check for next position
  // in next recursive iteration
  index++;

  // Recur for remaining list
  return searchElement (head->next, item, index);
}

int main ()
{
  int item;

  //creating 4 pointers of type struct Node
  //So these can point to address of struct type variable
  struct Node *head = NULL;
  struct Node *node2 = NULL;
  struct Node *node3 = NULL;
  struct Node *node4 = NULL;

  // allocate 3 nodes in the heap 
  head = (struct Node *) malloc (sizeof (struct Node));
  node2 = (struct Node *) malloc (sizeof (struct Node));
  node3 = (struct Node *) malloc (sizeof (struct Node));
  node4 = (struct Node *) malloc (sizeof (struct Node));


  head->data = 10;		// data set for head node 
  head->next = node2;		// next pointer assigned to address of node2 

  node2->data = 15;
  node2->next = node3;

  node3->data = 20;
  node3->next = node4;

  node4->data = 25;
  node4->next = NULL;

  printf ("Linked List: ");
  display (head);

  printf ("Enter element to search: ");
  scanf ("%d", &item);

  int index = searchElement (head, item, 0);

  if (index == -1)
    printf ("Item not found");
  else
    printf ("Item found at position: %d", index + 1);

  return 0;
}

Output

Linked List: 10 15 20 25 
Enter element to search: 10
Item found at position: 1