A Linked List is a linear data structure that consists of two parts: one is the data part and the other is the address part. In this article, all the common operations of a singly linked list are discussed in one menu-driven program.
Operations to be Performed
- createList(): To create the list with the 'n' number of nodes initially as defined by the user.
- traverse(): To see the contents of the linked list, it is necessary to traverse the given linked list. The given traverse() function traverses and prints the content of the linked list.
- insertAtFront(): This function simply inserts an element at the front/beginning of the linked list.
- insertAtEnd(): This function inserts an element at the end of the linked list.
- insertAtPosition(): This function inserts an element at a specified position in the linked list.
- deleteFirst(): This function simply deletes an element from the front/beginning of the linked list.
- deleteEnd(): This function simply deletes an element from the end of the linked list.
- deletePosition(): This function deletes an element from a specified position in the linked list.
- maximum(): This function finds the maximum element in a linked list.
- mean(): This function finds the mean of the elements in a linked list.
- sort(): This function sorts the given linked list in ascending order.
- reverseLL(): This function reverses the given linked list.
- display(): This function displays the linked list.
- search(): This function searches for an element user wants to search.
Below is the implementation of the above operations:
// C program for the all operations in
// the Singly Linked List
#include <stdio.h>
#include <stdlib.h>
// Linked List Node
struct node {
int info;
struct node* link;
};
struct node* start = NULL;
// Function to create list with n nodes initially
void createList()
{
if (start == NULL) {
int n;
printf("\nEnter the number of nodes: ");
scanf("%d", &n);
if (n != 0) {
int data;
struct node* newnode;
struct node* temp;
newnode = malloc(sizeof(struct node));
newnode->link = NULL;
start = newnode;
temp = start;
printf("\nEnter number to"
" be inserted : ");
scanf("%d", &data);
start->info = data;
for (int i = 2; i <= n; i++) {
newnode = malloc(sizeof(struct node));
newnode->link = NULL;
temp->link = newnode;
printf("\nEnter number to"
" be inserted : ");
scanf("%d", &data);
newnode->info = data;
temp = temp->link;
}
}
printf("\nThe list is created\n");
}
else
printf("\nThe list is already created\n");
}
// Function to traverse the linked list
void traverse()
{
struct node* temp;
// List is empty
if (start == NULL)
printf("\nList is empty\n");
// Else print the LL
else {
temp = start;
while (temp != NULL) {
printf("Data = %d\n", temp->info);
temp = temp->link;
}
}
}
// Function to insert at the front
// of the linked list
void insertAtFront()
{
int data;
struct node* temp;
temp = malloc(sizeof(struct node));
printf("\nEnter number to"
" be inserted : ");
scanf("%d", &data);
temp->info = data;
// Pointer of temp will be
// assigned to start
temp->link = start;
start = temp;
}
// Function to insert at the end of
// the linked list
void insertAtEnd()
{
int data;
struct node *temp, *head;
temp = malloc(sizeof(struct node));
// Enter the number
printf("\nEnter number to"
" be inserted : ");
scanf("%d", &data);
// Changes links
temp->link = 0;
temp->info = data;
head = start;
while (head->link != NULL) {
head = head->link;
}
head->link = temp;
}
// Function to insert at any specified
// position in the linked list
void insertAtPosition()
{
struct node *temp, *newnode;
int pos, data, i = 1;
newnode = malloc(sizeof(struct node));
// Enter the position and data
printf("\nEnter position and data :");
scanf("%d %d", &pos, &data);
// Change Links
temp = start;
newnode->info = data;
newnode->link = 0;
while (i < pos - 1) {
temp = temp->link;
i++;
}
newnode->link = temp->link;
temp->link = newnode;
}
// Function to delete from the front
// of the linked list
void deleteFirst()
{
struct node* temp;
if (start == NULL)
printf("\nList is empty\n");
else {
temp = start;
start = start->link;
free(temp);
}
}
// Function to delete from the end
// of the linked list
void deleteEnd()
{
struct node *temp, *prevnode;
if (start == NULL)
printf("\nList is Empty\n");
else {
temp = start;
while (temp->link != 0) {
prevnode = temp;
temp = temp->link;
}
free(temp);
prevnode->link = 0;
}
}
// Function to delete from any specified
// position from the linked list
void deletePosition()
{
struct node *temp, *position;
int i = 1, pos;
// If LL is empty
if (start == NULL)
printf("\nList is empty\n");
// Otherwise
else {
printf("\nEnter index : ");
// Position to be deleted
scanf("%d", &pos);
position = malloc(sizeof(struct node));
temp = start;
// Traverse till position
while (i < pos - 1) {
temp = temp->link;
i++;
}
// Change Links
position = temp->link;
temp->link = position->link;
// Free memory
free(position);
}
}
// Function to find the maximum element
// in the linked list
void maximum()
{
int a[10];
int i;
struct node* temp;
// If LL is empty
if (start == NULL)
printf("\nList is empty\n");
// Otherwise
else {
temp = start;
int max = temp->info;
// Traverse LL and update the
// maximum element
while (temp != NULL) {
// Update the maximum
// element
if (max < temp->info)
max = temp->info;
temp = temp->link;
}
printf("\nMaximum number "
"is : %d ",
max);
}
}
// Function to find the mean of the
// elements in the linked list
void mean()
{
int a[10];
int i;
struct node* temp;
// If LL is empty
if (start == NULL)
printf("\nList is empty\n");
// Otherwise
else {
temp = start;
// Stores the sum and count of
// element in the LL
int sum = 0, count = 0;
float m;
// Traverse the LL
while (temp != NULL) {
// Update the sum
sum = sum + temp->info;
temp = temp->link;
count++;
}
// Find the mean
m = sum / count;
// Print the mean value
printf("\nMean is %f ", m);
}
}
// Function to sort the linked list
// in ascending order
void sort()
{
struct node* current = start;
struct node* index = NULL;
int temp;
// If LL is empty
if (start == NULL) {
return;
}
// Else
else {
// Traverse the LL
while (current != NULL) {
index = current->link;
// Traverse the LL nestedly
// and find the minimum
// element
while (index != NULL) {
// Swap with it the value
// at current
if (current->info > index->info) {
temp = current->info;
current->info = index->info;
index->info = temp;
}
index = index->link;
}
// Update the current
current = current->link;
}
}
}
// Function to reverse the linked list
void reverseLL()
{
struct node *t1, *t2, *temp;
t1 = t2 = NULL;
// If LL is empty
if (start == NULL)
printf("List is empty\n");
// Else
else {
// Traverse the LL
while (start != NULL) {
// reversing of points
t2 = start->link;
start->link = t1;
t1 = start;
start = t2;
}
start = t1;
// New head Node
temp = start;
printf("Reversed linked "
"list is : ");
// Print the LL
while (temp != NULL) {
printf("%d ", temp->info);
temp = temp->link;
}
}
}
// Function to search an element in linked list
void search()
{
int found = -1;
// creating node to traverse
struct node* tr = start;
// first checking if the list is empty or not
if (start == NULL) {
printf("Linked list is empty\n");
}
else {
printf("\nEnter the element you want to search: ");
int key;
scanf("%d", &key);
// checking by traversing
while (tr != NULL) {
// checking for key
if (tr->info == key) {
found = 1;
break;
}
// moving forward if not at this position
else {
tr = tr->link;
}
}
// printing found or not
if (found == 1) {
printf(
"Yes, %d is present in the linked list.\n",
key);
}
else {
printf("No, %d is not present in the linked "
"list.\n",
key);
}
}
}
// Driver Code
int main()
{
createList();
int choice;
while (1) {
printf("\n\t1 To see list\n");
printf("\t2 For insertion at"
" starting\n");
printf("\t3 For insertion at"
" end\n");
printf("\t4 For insertion at "
"any position\n");
printf("\t5 For deletion of "
"first element\n");
printf("\t6 For deletion of "
"last element\n");
printf("\t7 For deletion of "
"element at any position\n");
printf("\t8 To find maximum among"
" the elements\n");
printf("\t9 To find mean of "
"the elements\n");
printf("\t10 To sort element\n");
printf("\t11 To reverse the "
"linked list\n");
printf("\t12 Search an element in linked list\n");
printf("\t13 To exit\n");
printf("\nEnter Choice :\n");
scanf("%d", &choice);
switch (choice) {
case 1:
traverse();
break;
case 2:
insertAtFront();
break;
case 3:
insertAtEnd();
break;
case 4:
insertAtPosition();
break;
case 5:
deleteFirst();
break;
case 6:
deleteEnd();
break;
case 7:
deletePosition();
break;
case 8:
maximum();
break;
case 9:
mean();
break;
case 10:
sort();
break;
case 11:
reverseLL();
break;
case 12:
search();
break;
case 13:
exit(1);
break;
default:
printf("Incorrect Choice\n");
}
}
return 0;
}
Output:
Menu:
.png)
Insertion at the starting:
.png)
Insertion at the end:
Insertion at specific position:
Print the Linked List:
Maximum among Linked List:
Sorting the Linked List:
Reverse the Linked List:
Delete the first and last element with choice 5 and 6:
Searching the element with choice 12:
.png)
