﻿ C Program: Search an element in a circular linked list - w3resource

# C Exercises: Search an element in a circular linked list

## C Doubly Linked List : Exercise-19 with Solution

Write a program in C to search an element in a circular linked list.

Visual Presentation:

Sample Solution:

C Code:

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

// Structure definition for a node in a circular linked list
struct node {
int num;
struct node *nextptr;
}*stnode, *ennode;

// Function prototypes
void ClListcreation(int n);
int FindElement(int FindElem, int n);
void displayClList();

int main() {
int n, m;
int FindElem, FindPlc;
stnode = NULL;
ennode = NULL;

// User input for the number of nodes
printf("\n\n Circular Linked List : Search an element in a circular linked list :\n");
printf("-------------------------------------------------------------------------\n");
printf(" Input the number of nodes : ");
scanf("%d", &n);
m = n;

// Creating a circular linked list
ClListcreation(n);
displayClList();

// Input for the element to find in the list
printf(" Input the element you want to find : ");
scanf("%d", &FindElem);

// Searching for the element in the list
FindPlc = FindElement(FindElem, m);
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");

return 0;
}

// Function to create a circular linked list
void ClListcreation(int n) {
int i, num;
struct node *preptr, *newnode;

if (n >= 1) {
stnode = (struct node *)malloc(sizeof(struct node));

// Input for the first node
printf(" Input data for node 1 : ");
scanf("%d", &num);
stnode->num = num;
stnode->nextptr = NULL;
preptr = stnode;

// Loop to create subsequent nodes and link them to form a circular list
for (i = 2; i <= n; i++) {
newnode = (struct node *)malloc(sizeof(struct node));
printf(" Input data for node %d : ", i);
scanf("%d", &num);
newnode->num = num;
newnode->nextptr = NULL;
preptr->nextptr = newnode;
preptr = newnode;
}
preptr->nextptr = stnode; // Last node linking with the first node to form a circular list
}
}

// Function to find an element in the circular linked list
int FindElement(int FindElem, int a) {
int ctr = 1;
ennode = stnode;

// Loop to search for the element
while (ennode->nextptr != NULL) {
if (ennode->num == FindElem)
break;
else {
ctr++;
ennode = ennode->nextptr;
if (ctr == a + 1)
break;
}
}
return ctr;
}

// Function to display the circular linked list
void displayClList() {
struct node *tmp;
int n = 1;

if (stnode == NULL) {
printf(" No data found in the List yet.");
} else {
tmp = stnode;
printf("\n\n Data entered in the list are :\n");

// Loop to display nodes in the circular list
do {
printf(" Data %d = %d\n", n, tmp->num);
tmp = tmp->nextptr;
n++;
} while (tmp != stnode);
}
}
```
```

Sample Output:

``` Circular Linked List : Search an element in a circular 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 : 9

Data entered in the list are :
Data 1 = 2
Data 2 = 5
Data 3 = 9
Input the element you want to find : 5
Element found at node 2
```

Flowchart :

ClListcreation() :

FindElement() :

displayClList() :

C Programming Code Editor:

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