Program to create, insert, delete and display operations on singly linked list in java

Linked List Operations: Traverse, Insert and Delete

In this tutorial, you will learn different operations on a linked list. Also, you will find implementation of linked list operations in C/C++, Python and Java.

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Linked List Operations: Traverse, Insert and Delete
Things to Remember about Linked List
Menu driven program for all operations on singly linked list in C
Singly Linked List Example Program in C
Singly Linked List Operations
Singly Linked List Example Program ( Insert, Delete, Display and Count)
Singly Linked List Java Example
Types of Linked List and Operation on Linked List
Video liên quan

There are various linked list operations that allow us to perform different actions on linked lists. For example, the insertion operation adds a new element to the linked list.

Here's a list of basic linked list operations that we will cover in this article.

Traversal - access each element of the linked list
Insertion - adds a new element to the linked list
Deletion - removes the existing elements
Search - find a node in the linked list
Sort - sort the nodes of the linked list

Before you learn about linked list operations in detail, make sure to know about Linked List first.

Things to Remember about Linked List

head points to the first node of the linked list
next pointer of the last node is NULL, so if the next current node is NULL, we have reached the end of the linked list.

In all of the examples, we will assume that the linked list has three nodes 1 --->2 --->3 with node structure as below:

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

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 is discussed in one menu-driven program.

Operations to be performed:

createList(): To create the list with ‘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 sort the given linked list in ascending order.
reverseLL(): This function reverses the given linked list.

Below is the implementation of the above operations:

// C program for the all operations in
// the Singly Linked List
#include 
#include 
// 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));

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));

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;

}

}
}
// Driver Code

int main()
{

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 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:

exit(1);

break;

default:

printf("Incorrect Choice\n");

}

}

return 0;
}

Output:

Menu:

Program to create, insert, delete and display operations on singly linked list in java

Insertion at the starting:

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:

Article Tags :

Data Structures

Linked List

Technical Scripter

Delete a Linked List

Linked Lists

Linked-List-Sorting

Menu driven programs

Technical Scripter 2020

Practice Tags :

Data Structures

Linked List

Read Full Article

Singly Linked List Example Program in C

Singly Linked List Operations

Insert in Linked List
Delete node in Linked List based on position
Display Nodes in Linked List
Count Nodes in Linked List

Singly Linked List Example Program ( Insert, Delete, Display and Count)

/* Singly Linked List Example - All Operations Example Program Using Functions in C*/ /* Data Structure Programs,C Linked List Examples */ /* Singly Linked List Example - Insert,Delete,Display and Count Operations*/ #include #include #include struct node { int value; struct node *next; }; void insert(); void display(); void delete(); int count(); typedef struct node DATA_NODE; DATA_NODE *head_node, *first_node, *temp_node = 0, *prev_node, next_node; int data; int main() { int option = 0; printf("Singly Linked List Example - All Operations\n"); while (option < 5) { printf("\nOptions\n"); printf("1 : Insert into Linked List \n"); printf("2 : Delete from Linked List \n"); printf("3 : Display Linked List\n"); printf("4 : Count Linked List\n"); printf("Others : Exit()\n"); printf("Enter your option:"); scanf("%d", &option); switch (option) { case 1: insert(); break; case 2: delete(); break; case 3: display(); break; case 4: count(); break; default: break; } } return 0; } void insert() { printf("\nEnter Element for Insert Linked List : \n"); scanf("%d", &data); temp_node = (DATA_NODE *) malloc(sizeof (DATA_NODE)); temp_node->value = data; if (first_node == 0) { first_node = temp_node; } else { head_node->next = temp_node; } temp_node->next = 0; head_node = temp_node; fflush(stdin); } void delete() { int countvalue, pos, i = 0; countvalue = count(); temp_node = first_node; printf("\nDisplay Linked List : \n"); printf("\nEnter Position for Delete Element : \n"); scanf("%d", &pos); if (pos > 0 && pos <= countvalue) { if (pos == 1) { temp_node = temp_node -> next; first_node = temp_node; printf("\nDeleted Successfully \n\n"); } else { while (temp_node != 0) { if (i == (pos - 1)) { prev_node->next = temp_node->next; if(i == (countvalue - 1)) { head_node = prev_node; } printf("\nDeleted Successfully \n\n"); break; } else { i++; prev_node = temp_node; temp_node = temp_node -> next; } } } } else printf("\nInvalid Position \n\n"); } void display() { int count = 0; temp_node = first_node; printf("\nDisplay Linked List : \n"); while (temp_node != 0) { printf("# %d # ", temp_node->value); count++; temp_node = temp_node -> next; } printf("\nNo Of Items In Linked List : %d\n", count); } int count() { int count = 0; temp_node = first_node; while (temp_node != 0) { count++; temp_node = temp_node -> next; } printf("\nNo Of Items In Linked List : %d\n", count); return count; }

Singly Linked List Java Example

Posted by: Anmol Deep in Core Java May 26th, 2020 1 Comment

In this example, we shall discuss how to create a Singly Linked List in Java. We will also go through some live code demonstrating different operations on a Singly Linked List.

You can also check this tutorial in the following video:

Java LinkedList Tutorial – video

Types of Linked List and Operation on Linked List

In the previous blog, we have seen the structure and properties of a Linked List. In this blog, we will discuss the types of a linked list and basic operations that can be performed on a linked list.

Types of Linked List

Following are the types of linked list

Singly Linked List.
Doubly Linked List.
Circular Linked List.

Singly Linked List

A Singly-linked list is a collection of nodes linked together in a sequential way where each node of the singly linked list contains a data field and an address field that contains the reference of the next node.

The structure of the node in the Singly Linked List is

class Node { int data // variable to store the data of the node Node next // variable to store the address of the next node }

The nodes are connected to each other in this form where the value of the next variable of the last node is NULL i.e. next = NULL, which indicates the end of the linked list.

Doubly Linked List

A Doubly Linked List contains an extra memory to store the address of the previous node, together with the address of the next node and data which are there in the singly linked list. So, here we are storing the address of the next as well as the previous nodes.

The following is the structure of the node in the Doubly Linked List(DLL):

class DLLNode { int val // variable to store the data of the node DLLNode prev // variable to store the address of the previous node DLLNode next // variable to store the address of the next node }

The nodes are connected to each other in this form where the first node has prev = NULL and the last node has next = NULL.

Advantages over Singly Linked List-

It can be traversed both forward and backward direction.
The delete operation is more efficient if the node to be deleted is given. (Think! you will get the answer in the second half of this blog)
The insert operation is more efficient if the node is given before which insertion should take place. (Think!)

Disadvantages over Singly Linked List-

It will require more space as each node has an extra memory to store the address of the previous node.
The number of modification increase while doing various operations like insertion, deletion, etc.

Circular Linked List

A circular linked list is either a singly or doubly linked list in which there are no NULL values. Here, we can implement the Circular Linked List by making the use of Singly or Doubly Linked List. In the case of a singly linked list, the next of the last node contains the address of the first node and in case of a doubly-linked list, the next of last node contains the address of the first node and prev of the first node contains the address of the last node.

Advantages of a Circular linked list

The list can be traversed from any node.
Circular lists are the required data structure when we want a list to be accessed in a circle or loop.
We can easily traverse to its previous node in a circular linked list, which is not possible in a singly linked list. (Think!)

Disadvantages of Circular linked list

If not traversed carefully, then we could end up in an infinite loop because here we don't have any NULL value to stop the traversal.
Operations in a circular linked list are complex as compared to a singly linked list and doubly linked list like reversing a circular linked list, etc.

Basic Operations on Linked List

Traversal: To traverse all the nodes one after another.
Insertion: To add a node at the given position.
Deletion: To delete a node.
Searching: To search an element(s) by value.
Updating: To update a node.
Sorting: To arrange nodes in a linked list in a specific order.
Merging: To merge two linked lists into one.

We will see the various implementation of these operations on a singly linked list.

Following is the structure of the node in a linked list:

class Node{ int data // variable containing the data of the node Node next // variable containing the address of next node }

Linked List Traversal

The idea here is to step through the list from beginning to end. For example, we may want to print the list or search for a specific node in the list.

The algorithm for traversing a list

Start with the head of the list. Access the content of the head node if it is not null.
Then go to the next node(if exists) and access the node information
Continue until no more nodes (that is, you have reached the null node)

void traverseLL(Node head) { while(head != NULL) { print(head.data) head = head.next } }

Linked List node Insertion

There can be three cases that will occur when we are inserting a node in a linked list.

Insertion at the beginning
Insertion at the end. (Append)
Insertion after a given node

Insertion at the beginning

Since there is no need to find the end of the list. If the list is empty, we make the new node as the head of the list. Otherwise, we we have to connect the new node to the current head of the list and make the new node, the head of the list.

// function is returning the head of the singly linked-list Node insertAtBegin(Node head, int val) { newNode = new Node(val) // creating new node of linked list if(head == NULL) // check if linked list is empty return newNode else // inserting the node at the beginning { newNode.next = head return newNode } }

Insertion at end

We will traverse the list until we find the last node. Then we insert the new node to the end of the list. Note that we have to consider special cases such as list being empty.

In case of a list being empty, we will return the updated head of the linked list because in this case, the inserted node is the first as well as the last node of the linked list.

// the function is returning the head of the singly linked list Node insertAtEnd(Node head, int val) { if( head == NULL ) // handing the special case { newNode = new Node(val) head = newNode return head } Node temp = head // traversing the list to get the last node while( temp.next != NULL ) { temp = temp.next } newNode = new Node(val) temp.next = newNode return head }

Insertion after a given node

We are given the reference to a node, and the new node is inserted after the given node.

void insertAfter(Node prevNode, int val) { newNode = new Node(val) newNode.next = prevNode.next prevNode.next = newNode }

NOTE: If the address of the prevNode is not given, then you can traverse to that node by finding the data value.

Linked List node Deletion

To delete a node from a linked list, we need to do these steps

Find the previous node of the node to be deleted.
Change the next pointer of the previous node
Free the memory of the deleted node.

In the deletion, there is a special case in which the first node is deleted. In this, we need to update the head of the linked list.

// this function will return the head of the linked list Node deleteLL(Node head, Node del) { if(head == del) // if the node to be deleted is the head node { return head.next // special case for the first Node } Node temp = head while( temp.next != NULL ) { if(temp.next == del) // finding the node to be deleted { temp.next = temp.next.next delete del // free the memory of that Node return head } temp = temp.next } return head // if no node matches in the Linked List }

Linked List node Searching

To search any value in the linked list, we can traverse the linked list and compares the value present in the node.

bool searchLL(Node head, int val) { Node temp = head // creating a temp variable pointing to the head of the linked list while( temp != NULL) // traversing the list { if( temp.data == val ) return true temp = temp.next } return false }

Linked List node Updation

To update the value of the node, we just need to set the data part to the new value.

Below is the implementation in which we had to update the value of the first node in which data is equal to val and we have to set it to newVal.

void updateLL(Node head, int val, int newVal) { Node temp = head while(temp != NULL) { if( temp.data == val) { temp.data = newVal return } temp = temp.next } }

Program to create, insert, delete and display operations on singly linked list in java

Linked List Operations: Traverse, Insert and Delete

Things to Remember about Linked List

Menu driven program for all operations on singly linked list in C

Singly Linked List Example Program in C

Singly Linked List Operations

Singly Linked List Example Program ( Insert, Delete, Display and Count)

Singly Linked List Java Example

Types of Linked List and Operation on Linked List

Types of Linked List

Singly Linked List

Doubly Linked List

Circular Linked List

Basic Operations on Linked List

Linked List Traversal

Linked List node Insertion

Linked List node Deletion

Linked List node Searching

Linked List node Updation

Suggested Problems to solve in Linked List

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