Description

To delete a given node from singly linked list - 
Case 1: check if list is empty 
	Show message that list is empty.
Case 2: When list has only one element
	Assign the NULL value to the head and free the memory occupied by node
Case 3: When to delete first element of list
	Step 1: Assign the address of head to temporary variable
	Step 2: Assign the address of second node to the head
	Step 3: Free the memory occupied by first node
Case 4: When to delete any other node
	Step 1: Traverse the list untill to reach last element
	Step 2: Maintain one more field to store the address of previous node
	Step 3: Assign the address conatined by next field of given node to address 
	field of previous node of given node to delete.
	Step 4: Free the memory occupied by given node

Note: Here head contains the address of first node

C/C++

/* C Program To Delete a Given Node In singly linked list */
//Save it as delete_given_node_singly_linked_list.java


#include<stdio.h>
#include<malloc.h>
struct node *create(int);
void display(struct node *);
struct node *delete_given_node(struct node *);

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

int main(){
    int n;
    struct node *head;
    printf("Enter number of nodes : ");
    scanf("%d",&n);
    
    //Calling function to create node
    head=create(n);
    
    //Calling function to display list
    display(head);
    
    //Code to delete a given node
    head=delete_given_node(head);
    printf("\nThe linked list after deletion of a given node - \n");
    
    //Calling function to display list after deletion of a given node
    display(head);

    return 0;
}

struct node *create(int n){
    int i;
    struct node *head=NULL;
    struct node *ptr,*newNode;

    for(i=0;i<n;i++){
        
        //Creating a new node
        newNode=(struct node*)malloc(sizeof(struct node*));
        
        //Assigning data to newly created node
        printf("Enter the value of %d node : ",i+1);
        scanf("%d",&newNode->data);
        newNode->next=NULL;
        
        /*If list is empty assign the address of newly created node to head*/
        if(head==NULL){
            head=newNode;
        }else{
            
            /* If list already have few elements then loop through
            list and add newly created node after given node*/
            ptr=head;
            while(ptr->next!=NULL){
                ptr=ptr->next;
            }
            ptr->next=newNode;
        }
    }
    return head;
}

void display(struct node *head){
    struct node *ptr;
    
    //If list is empty
    if(head==NULL){
        printf("The linked list is empty");
    }else{
        
        /*If list has elements then loop through the loop and
        print elements one by one in sequential manner*/
        ptr=head;
        while(ptr!=NULL){
            printf("The node value = %d and their address = %u\n",ptr->data,ptr);
            ptr=ptr->next;
        }
    }
}

//Function to delete a given node
struct node *delete_given_node(struct node *head){
    int val;
    struct node *preptr, *ptr;
    
    //If list has no any node give proper message
    if(head==NULL){
        printf("\nNo node available to delete!!");
    }else if(head->next==NULL){
        
        //If node have only one node
        printf("Enter the value of the node to delete : ");
        scanf("%d",&val);
        ptr=head;
        if(val==head->data){
            head=NULL;
            free(ptr);
        }else{
            printf("Node cannot be deleted!!");
        }

    }else{
        printf("Enter the value of the node to delete : ");
        scanf("%d",&val);
        
        //If first node to be deleted
        if(val==head->data){
            ptr=head;
            head=ptr->next;
            free(ptr);
        }else{
            
            //If to delete other node
            ptr=head;
            while(ptr->data!=val){
                preptr=ptr;
                ptr=ptr->next;
            }
            preptr->next=ptr->next;
            free(ptr);
        }
    }
    return head;
}

Input:
Enter number of nodes : 4
Enter the value of 1 node : 2
Enter the value of 2 node : 5
Enter the value of 3 node : 4
Enter the value of 4 node : 7
The node value = 2 and their address = 7212376
The node value = 5 and their address = 7212408
The node value = 4 and their address = 7212424
The node value = 7 and their address = 7212440
Enter the value of the node to delete : 2

Output:
The linked list after deletion of a given node -
The node value = 5 and their address = 7212408
The node value = 4 and their address = 7212424
The node value = 7 and their address = 7212440

Java

/* Java Program To Delete a Given Node In singly linked list */
//Save it as DeleteGivenNodeSinglyLinkedList.java

import java.io.*;
import java.util.Scanner;
public class DeleteGivenNodeSinglyLinkedList {
    
    // Declaring node
    class Node {
        int data;
        Node next;

        public Node(int data) {
            this.data = data;
            
            // Assigning null value to the next field
            this.next = null;
        }
    }

    public Node head = null;
    
    // Function to add node
    public void addNode(int data) {
        
        // Creating a new node
        Node newNode = new Node(data);
        
        /* If list is empty assign the address of newly created node to head */
        if (head == null) {
            head = newNode;
        } else {
            
            /*
             * If list already have few elements then loop through list and
             */
            Node ptr = head;
            while (ptr.next != null) {
                ptr = ptr.next;
            }
            ptr.next = newNode;
        }
    }

    public void display() {
        Node ptr = head;
        
        // If list is empty
        if (ptr == null) {
            System.out.println("The list is empty");
            return;
        }
        System.out.println("The nodes of lists are : ");
        
        /*
         If list has elements then loop through the loop and print 
         elements one by one in sequential manner
         */
        while (ptr != null) {
            System.out.print(ptr.data + " ");
            ptr = ptr.next;
        }
    }

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        DeleteGivenNodeSinglyLinkedList list = 
                           new DeleteGivenNodeSinglyLinkedList();

        System.out.println("Enter number of node you want to enter : ");
        int n = scanner.nextInt();

        for (int i = 0; i < n; i++) {
            System.out.println("Enter value of " + (i + 1) + " node : ");
            int val = scanner.nextInt();
            list.addNode(val);
        }
        
        // Calling function to display list
        list.display();
        
        System.out.println("\nEnter the value given node to delete : ");
        int val=scanner.nextInt();

        list.delete_given_node(val);
        
        // Calling function to display list after deletion of a given node
        System.out.println("\nAfter deletion of a given node - ");
        list.display();
    }
    
    //Method to delete a given node
    private void delete_given_node(int val) {
        Node preptr = null, ptr;
        
        //If list has no node
        if(head==null) {
            System.out.println("No node available to delete!!");
        }
        
        //If list has only one node
        else if(head.next==null) {
            ptr=head;
            head=ptr.next;
        }
        
        //To delete first node of list
        else {
            if(val==head.data) {
                ptr=head;
                head=ptr.next;
            }
            
            //To delete any node from list
            else {
                ptr=head;
                while(ptr.data!=val) {
                    preptr=ptr;
                    ptr=ptr.next;
                }
                preptr.next=ptr.next;
            }
        }
    }
}

Input:
Enter number of node you want to enter : 
4
Enter value of 1 node : 
2
Enter value of 2 node : 
5
Enter value of 3 node : 
4
Enter value of 4 node : 
7
The nodes of lists are : 
2 5 4 7 
Enter the value given node to delete : 
4

Output:
After deletion of a given node - 
The nodes of lists are : 
2 5 7

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