﻿ C Program: Search an element in a Singly Linked List - w3resource

# C Exercises: Search an element in a Singly Linked List

## C Singly Linked List : Exercise-10 with Solution

Write a program in C to search for an existing element in a singly linked list.

Visual Presentation:

Sample Solution:

C Code:

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

// Define the structure for a node in a linked list
struct node
{
int num;                // Data of the node
struct node *nextptr;   // Pointer to the next node
};

// Declare pointers to the starting node and a temporary node
struct node stnode, *ennode;

// Function to find an element in the linked list and return its position
int FindElement(int);

int main()
{
int n, i, FindElem, FindPlc;

// Initialize the starting node's pointer to NULL
stnode.nextptr = NULL;

// Point ennode to the starting node
ennode = &stnode;

printf("\n\n Linked List : Search an element in a Singly Linked List :\n");
printf("---------------------------------------------------------------\n");

printf(" Input the number of nodes : ");
scanf("%d", &n);

printf("\n");
// Loop to create the linked list with user input data
for (i = 0; i < n; i++)
{
// Allocate memory for the next node
ennode->nextptr = (struct node *)malloc(sizeof(struct node));

printf(" Input data for node %d : ", i + 1);
scanf("%d", &ennode->num);

ennode = ennode->nextptr;
}
ennode->nextptr = NULL;

printf("\n Data entered in the list are :\n");

// Reset ennode to the starting node
ennode = &stnode;

// Loop to display the data entered in the linked list
while (ennode->nextptr != NULL)
{
printf(" Data = %d\n", ennode->num);
ennode = ennode->nextptr;
}

printf("\n");

printf(" Input the element to be searched : ");
scanf("%d", &FindElem);

// Call FindElement function to search for the element and get its position
FindPlc = FindElement(FindElem);

// Display the position of the found element or a message if it doesn't exist
if (FindPlc <= n)
printf(" Element found at node %d \n\n", FindPlc);
else
printf(" This element does not exist in the linked list.\n\n");
}

// Function to find an element in the linked list and return its position
int FindElement(int FindElem)
{
int ctr = 1;

// Reset ennode to the starting node
ennode = &stnode;

// Loop to traverse the linked list and find the element
while (ennode->nextptr != NULL)
{
// Check if the element is found at the current node
if (ennode->num == FindElem)
break;
else
{
ctr++;
ennode = ennode->nextptr;
}
}
return ctr; // Return the position of the found element
}
```
```

Sample Output:

``` Linked List : Search an element in a  Singly Linked List :
---------------------------------------------------------------
Input the number of nodes : 3

Input data for node 1 : 2
Input data for node 2 : 5
Input data for node 3 : 8

Data entered in the list are :
Data = 2
Data = 5
Data = 8

Input the element to be searched : 5
Element found at node 2
```

Flowchart:

FindElement() :

C Programming Code Editor:

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