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Delete last occurrence of an item from linked list

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Using pointers, loop through the whole list and keep track of the node prior to the node containing the last occurrence key using a special pointer. After this just store the next of next of the special pointer, into to next of special pointer to remove the required node from the linked list.

C++




#include <iostream>
#include <bits/stdc++.h>
using namespace std;
  
// A linked list Node
struct Node 
{
    int data;
    struct Node* next;
};
  
// Function to delete the last occurrence
void deleteLast(struct Node** head, int x)
{
    struct Node** tmp1 = NULL;
    while (*head)
    {
            if ((*head)->data == x) 
            {
                tmp1 = head;
            }
            head = &(*head)->next;
    }
    if (tmp1)
    {
        struct Node* tmp = *tmp1;
        *tmp1 = tmp->next;
        free(tmp);
    }
}
  
// Utility function to create a new node with
// given key 
struct Node* newNode(int x)
{
    Node* node = new Node ;
    node->data = x;
    node->next = NULL;
    return node;
}
  
// This function prints contents of linked
// list starting from the given Node
void display(struct Node* head)
{
    struct Node* temp = head;
    if (head == NULL)
    {
        cout << "NULL\n";
        return;
    }
    while (temp != NULL)
    {
        cout << temp->data <<" --> ";
        temp = temp->next;
    }
    cout << "NULL\n";
}
  
// Driver code
int main()
{
    struct Node* head = newNode(1);
    head->next = newNode(2);
    head->next->next = newNode(3);
    head->next->next->next = newNode(4);
    head->next->next->next->next = newNode(5);
    head->next->next->next->next->next = newNode(4);
    head->next->next->next->next->next->next = newNode(4);
      
    cout << "Created Linked list: ";
    display(head);
      
    // Pass the address of the head pointer
    deleteLast(&head, 4);   
    cout << "List after deletion of 4: ";
      
    display(head);
      
    return 0;
}
  
// This code is contributed by khushboogoyal499


C




#include <stdio.h>
#include <stdlib.h>
  
// A linked list Node
struct Node {
    int data;
    struct Node* next;
};
  
// Function to delete the last occurrence
void deleteLast(struct Node** head, int x)
{
        struct Node** tmp1 = NULL;
        while(*head) {
                if((*head)->data == x) {
                        tmp1 = head;
                }
                head = &(*head)->next;
        }
        if(tmp1) {
                struct Node* tmp = *tmp1;
                *tmp1 = tmp->next;
                free(tmp);
        }
}
  
/* Utility function to create a new node with
given key */
struct Node* newNode(int x)
{
    struct Node* node = malloc(sizeof(struct Node*));
    node->data = x;
    node->next = NULL;
    return node;
}
  
// This function prints contents of linked list
// starting from the given Node
void display(struct Node* head)
{
    struct Node* temp = head;
    if (head == NULL) {
        printf("NULL\n");
        return;
    }
    while (temp != NULL) {
        printf("%d --> ", temp->data);
        temp = temp->next;
    }
    printf("NULL\n");
}
  
/* Driver program to test above functions*/
int main()
{
    struct Node* head = newNode(1);
    head->next = newNode(2);
    head->next->next = newNode(3);
    head->next->next->next = newNode(4);
    head->next->next->next->next = newNode(5);
    head->next->next->next->next->next = newNode(4);
    head->next->next->next->next->next->next = newNode(4);
    printf("Created Linked list: ");
    display(head);
    deleteLast(&head, 4);   // Pass the address of the head pointer
    printf("List after deletion of 4: ");
    display(head);
    return 0;
}


Java




import java.io.*;
   
// A linked list Node
class Node
{
    int data; 
    Node next;
      
    Node(int data)
    {
        this.data = data;
        this.next = null;
    }
}
  
class GFG{
  
// Function to delete the last occurrence
static Node deleteLast(Node head,int x)
{
    Node temp = head;
    Node ptr = null;
      
    while (temp != null)
    {
          
        // If found key, update
        if (temp.data == x)
            ptr = temp;
              
        temp = temp.next;
    }
    
    // If the last occurrence is the last node
    if (ptr != null && ptr.next == null)
    {
        temp = head;
          
        while (temp.next != ptr)
        {
            temp = temp.next;
        }
        temp.next = null;
    }
      
    // If it is not the last node
    if (ptr != null && ptr.next != null)
    {
        ptr.data = ptr.next.data;
        temp = ptr.next;
        ptr.next = ptr.next.next;
    }
    return head;
}
  
// This function prints contents of linked list
// starting from the given Node
static void display(Node head)
{
    Node temp = head;
    if (head == null)
    {
        System.out.print("NULL\n");
        return;
    }
    while (temp != null)
    {
        System.out.print( temp.data+" --> ");
        temp = temp.next;
    }
    System.out.print("NULL\n");
}
  
// Driver code
public static void main(String[] args)
{
    Node head = new Node(1);
    head.next = new Node(2);
    head.next.next = new Node(3);
    head.next.next.next = new Node(4);
    head.next.next.next.next = new Node(5);
    head.next.next.next.next.next = new Node(4);
    head.next.next.next.next.next.next = new Node(4);
      
    System.out.print("Created Linked list: ");
    display(head);
      
    // Pass the address of the head pointer
    head = deleteLast(head, 4);
    System.out.print("List after deletion of 4: ");
    display(head);
}
}
  
// This code is contributed by patel2127


C#




// C# program for the above approach
  
using System;
  
public class GFG {
  
    // A linked list Node
    public class Node {
        public int data;
        public Node next;
        public Node(int data)
        {
            this.data = data;
            this.next = null;
        }
    }
  
    // Function to delete the last occurrence.
    static Node deleteLast(Node head, int x)
    {
        Node temp = head;
        Node ptr = null;
  
        while (temp != null) {
  
            // If found key, update
            if (temp.data == x)
                ptr = temp;
  
            temp = temp.next;
        }
  
        // If the last occurrence is the last node
        if (ptr != null && ptr.next == null) {
            temp = head;
  
            while (temp.next != ptr) {
                temp = temp.next;
            }
            temp.next = null;
        }
  
        // If it is not the last node
        if (ptr != null && ptr.next != null) {
            ptr.data = ptr.next.data;
            temp = ptr.next;
            ptr.next = ptr.next.next;
        }
        return head;
    }
  
    // This function prints contents of linked list starting
    // from the given Node.
    static void display(Node head)
    {
        Node temp = head;
        if (head == null) {
            Console.Write("NULL\n");
            return;
        }
        while (temp != null) {
            Console.Write(temp.data + " --> ");
            temp = temp.next;
        }
        Console.Write("NULL\n");
    }
  
    static public void Main()
    {
  
        // Code
        Node head = new Node(1);
        head.next = new Node(2);
        head.next.next = new Node(3);
        head.next.next.next = new Node(4);
        head.next.next.next.next = new Node(5);
        head.next.next.next.next.next = new Node(4);
        head.next.next.next.next.next.next = new Node(4);
  
        Console.Write("Created Linked list: ");
        display(head);
  
        // Pass the address of the head pointer
        head = deleteLast(head, 4);
        Console.Write("List after deletion of 4: ");
        display(head);
    }
}
  
// This code is contributed by lokesh (lokeshmvs21).


Python3




# A linked list Node
class Node: 
    def __init__(self, new_data): 
          
        self.data = new_data 
        self.next = None
  
# Function to delete the last occurrence
def deleteLast(head, x):
  
    temp = head
    ptr = None
      
    while (temp != None): 
          
        # If found key, update
        if (temp.data == x):
            ptr = temp     
              
        temp = temp.next
      
    # If the last occurrence is the last node
    if (ptr != None and ptr.next == None): 
        temp = head
        while (temp.next != ptr):
            temp = temp.next
              
        temp.next = None
      
    # If it is not the last node
    if (ptr != None and ptr.next != None): 
        ptr.data = ptr.next.data
        temp = ptr.next
        ptr.next = ptr.next.next
          
    return head
      
# Utility function to create a new node
# with given key 
def newNode(x):
  
    node = Node(0)
    node.data = x
    node.next = None
    return node
  
# This function prints contents of linked 
# list starting from the given Node
def display(head):
  
    temp = head
      
    if (head == None): 
        print("NULL\n")
        return
      
    while (temp != None): 
        print( temp.data," --> ", end = "")
        temp = temp.next
      
    print("NULL")
  
# Driver code
head = newNode(1)
head.next = newNode(2)
head.next.next = newNode(3)
head.next.next.next = newNode(4)
head.next.next.next.next = newNode(5)
head.next.next.next.next.next = newNode(4)
head.next.next.next.next.next.next = newNode(4)
  
print("Created Linked list: ", end = '')
display(head)
  
# Pass the address of the head pointer
head = deleteLast(head, 4
print("List after deletion of 4: ", end = '')
  
display(head)
  
# This code is contributed by rutvik_56


Javascript




<script>
// A linked list Node
class Node
{
  
    // Utility function to create a new node
    // with given key
    constructor(data)
    {
        this.data = data;
        this.next = null;
         
    }
}
  
// Function to delete the last occurrence
function deleteLast(head, x)
{
    let temp = head;
    let prt = null;
     while (temp != null)
     {
         //If found key, update
         if (temp.data == x)
            ptr = temp;
        temp = temp.next;
     }
       
     // If the last occurrence is the last node
     if (ptr != null && ptr.next == null)
     {
         temp = head;
        while (temp.next != ptr)
        {
            temp = temp.next;
        }
        temp.next = null;
     }
       
     // If it is not the last node
     if (ptr != null && ptr.next != null)
     {
         ptr.data = ptr.next.data;
        temp = ptr.next;
        ptr.next = ptr.next.next;
          
     }
     return head;
      
}
  
// This function prints contents of linked
// list starting from the given Node
function display(head)
{
    let temp = head
    if (head == null)
    {
        document.write("NULL<br>");
        return;
    }
    while (temp != null)
    {
        document.write( temp.data," --> ", end = "");
        temp = temp.next;
    }
    document.write("NULL<br>")
}
  
// Driver code
let head = new Node(1)
head.next = new Node(2)
head.next.next = new Node(3)
head.next.next.next = new Node(4)
head.next.next.next.next = new Node(5)
head.next.next.next.next.next = new Node(4)
head.next.next.next.next.next.next = new Node(4);
  
document.write("Created Linked list: ");
display(head)
  
// Pass the address of the head pointer
head = deleteLast(head, 4)
document.write("List after deletion of 4: ")
display(head)
  
// This code is contributed by avanitrachhadiya2155
</script>


Output

Created Linked list: 1 --> 2 --> 3 --> 4 --> 5 --> 4 --> 4 --> NULL
List after deletion of 4: 1 --> 2 --> 3 --> 4 --> 5 --> 4 --> NULL

Time Complexity: O(n)

Auxiliary Space: O(1)

Given a linked list and a key to be deleted. Delete last occurrence of key from linked. The list may have duplicates.

Examples:  

Input:   1->2->3->5->2->10, key = 2
Output:  1->2->3->5->10

The idea is to traverse the linked list from beginning to end. While traversing, keep track of last occurrence key. After traversing the complete list, delete the last occurrence by copying data of next node and deleting the next node.  

C++




// A C++ program to demonstrate deletion of last
// Node in singly linked list
#include <bits/stdc++.h>
  
// A linked list Node
struct Node {
    int key;
    struct Node* next;
};
  
void deleteLast(Node* head, int key)
{
    // Initialize previous of Node to be deleted
    Node* x = NULL;
  
    // Start from head and find the Node to be
    // deleted
    Node* temp = head;
    while (temp) {
        // If we found the key, update xv
        if (temp->key == key)
            x = temp;
  
        temp = temp->next;
    }
  
    // key occurs at-least once
    if (x != NULL) {
  
        // Copy key of next Node to x
        x->key = x->next->key;
  
        // Store and unlink next
        temp = x->next;
        x->next = x->next->next;
  
        // Free memory for next
        delete temp;
    }
}
  
/* Utility function to create a new node with
   given key */
Node* newNode(int key)
{
    Node* temp = new Node;
    temp->key = key;
    temp->next = NULL;
    return temp;
}
  
// This function prints contents of linked list
// starting from the given Node
void printList(struct Node* node)
{
    while (node != NULL) {
        printf(" %d ", node->key);
        node = node->next;
    }
}
  
/* Driver program to test above functions*/
int main()
{
    /* Start with the empty list */
    struct Node* head = newNode(1);
    head->next = newNode(2);
    head->next->next = newNode(3);
    head->next->next->next = newNode(5);
    head->next->next->next->next = newNode(2);
    head->next->next->next->next->next = newNode(10);
  
    puts("Created Linked List: ");
    printList(head);
    deleteLast(head, 2);
    puts("\nLinked List after Deletion of 2: ");
    printList(head);
    return 0;
}


Java




// A Java program to demonstrate deletion of last 
// Node in singly linked list 
class GFG
{
      
  
// A linked list Node 
static class Node 
    int key; 
    Node next; 
}; 
  
static Node deleteLast(Node head, int key) 
    // Initialize previous of Node to be deleted 
    Node x = null
  
    // Start from head and find the Node to be 
    // deleted 
    Node temp = head; 
    while (temp != null
    
        // If we found the key, update xv 
        if (temp.key == key) 
            x = temp; 
  
        temp = temp.next; 
    
  
    // key occurs at-least once 
    if (x != null
    
  
        // Copy key of next Node to x 
        x.key = x.next.key; 
  
        // Store and unlink next 
        temp = x.next; 
        x.next = x.next.next; 
  
        // Free memory for next 
    
    return head;
  
/// Utility function to create a new node with 
//given key /
static Node newNode(int key) 
    Node temp = new Node(); 
    temp.key = key; 
    temp.next = null
    return temp; 
  
// This function prints contents of linked list 
// starting from the given Node 
static void printList( Node node) 
    while (node != null
    
        System.out.printf(" %d ", node.key); 
        node = node.next; 
    
  
// Driver code/
public static void main(String args[])
    // /Start with the empty list /
    Node head = newNode(1); 
    head.next = newNode(2); 
    head.next.next = newNode(3); 
    head.next.next.next = newNode(5); 
    head.next.next.next.next = newNode(2); 
    head.next.next.next.next.next = newNode(10); 
  
    System.out.printf("Created Linked List: "); 
    printList(head); 
    deleteLast(head, 2); 
    System.out.printf("\nLinked List after Deletion of 2: "); 
    printList(head); 
}
  
// This code is contributed by Arnab Kundu


Python3




# Python3 program to demonstrate deletion of 
# last Node in singly linked list 
  
# A linked list Node 
class Node: 
  
    # Constructor to initialize the node object 
    def __init__(self, data): 
        self.data = data 
        self.next = None
  
def deleteLast(head, key) :
  
    # Initialize previous of Node to be deleted 
    x = None
  
    # Start from head and find the Node to be 
    # deleted 
    temp = head 
    while (temp != None) :
      
        # If we found the key, update xv 
        if (temp.key == key) :
            x = temp 
  
        temp = temp.next
      
    # key occurs at-least once 
    if (x != None) :
      
        # Copy key of next Node to x 
        x.key = x.next.key 
  
        # Store and unlink next 
        temp = x.next
        x.next = x.next.next
  
        # Free memory for next 
      
    return head
  
# Utility function to create 
# a new node with given key 
def newNode(key) :
  
    temp = Node(0
    temp.key = key 
    temp.next = None
    return temp 
  
# This function prints contents of linked list 
# starting from the given Node 
def printList( node) :
  
    while (node != None) :
      
        print ( node.key, end = " "
        node = node.next
      
# Driver Code 
if __name__=='__main__'
  
    # Start with the empty list 
    head = newNode(1
    head.next = newNode(2
    head.next.next = newNode(3
    head.next.next.next = newNode(5
    head.next.next.next.next = newNode(2
    head.next.next.next.next.next = newNode(10
  
    print("Created Linked List: "
    printList(head) 
    deleteLast(head, 2
      
    print("\nLinked List after Deletion of 2: "
    printList(head) 
  
# This code is contributed by Arnab Kundu


C#




// C# program to demonstrate deletion of last 
// Node in singly linked list 
using System;
  
class GFG 
      
  
// A linked list Node 
public class Node 
    public int key; 
    public Node next; 
}; 
  
static Node deleteLast(Node head, int key) 
    // Initialize previous of Node to be deleted 
    Node x = null
  
    // Start from head and find the Node to be 
    // deleted 
    Node temp = head; 
    while (temp != null
    
        // If we found the key, update xv 
        if (temp.key == key) 
            x = temp; 
  
        temp = temp.next; 
    
  
    // key occurs at-least once 
    if (x != null
    
  
        // Copy key of next Node to x 
        x.key = x.next.key; 
  
        // Store and unlink next 
        temp = x.next; 
        x.next = x.next.next; 
  
        // Free memory for next 
    
    return head; 
  
/// Utility function to create a new node with 
//given key / 
static Node newNode(int key) 
    Node temp = new Node(); 
    temp.key = key; 
    temp.next = null
    return temp; 
  
// This function prints contents of linked list 
// starting from the given Node 
static void printList( Node node) 
    while (node != null
    
        Console.Write(" {0} ", node.key); 
        node = node.next; 
    
  
// Driver code
public static void Main(String []args) 
    // Start with the empty list 
    Node head = newNode(1); 
    head.next = newNode(2); 
    head.next.next = newNode(3); 
    head.next.next.next = newNode(5); 
    head.next.next.next.next = newNode(2); 
    head.next.next.next.next.next = newNode(10); 
  
    Console.Write("Created Linked List: "); 
    printList(head); 
    deleteLast(head, 2); 
    Console.Write("\nLinked List after Deletion of 2: "); 
    printList(head); 
  
// This code has been contributed by 29AjayKumar


Javascript




<script>
  
// A Javascript program to demonstrate
// deletion of last Node in singly 
// linked list
class Node
{
    constructor(key)
    {
        this.key = key;
        this.next = null;
    }
}
  
function deleteLast(head, key)
{
      
    // Initialize previous of Node to be deleted
    let x = null;
   
    // Start from head and find the Node to be
    // deleted
    let temp = head;
      
    while (temp != null)
    {
          
        // If we found the key, update xv
        if (temp.key == key)
            x = temp;
   
        temp = temp.next;
    }
   
    // key occurs at-least once
    if (x != null)
    {
          
        // Copy key of next Node to x
        x.key = x.next.key;
   
        // Store and unlink next
        temp = x.next;
        x.next = x.next.next;
   
        // Free memory for next
    }
    return head;
}
  
// This function prints contents of linked
// list starting from the given Node
function printList(node)
{
    while (node != null)
    {
        document.write(node.key + " ");
        node = node.next;
    }
}
  
// Driver code
let head = new Node(1);
head.next = new Node(2);
head.next.next = new Node(3);
head.next.next.next = new Node(5);
head.next.next.next.next = new Node(2);
head.next.next.next.next.next = new Node(10);
  
document.write("Created Linked List: <br>");
printList(head);
deleteLast(head, 2);
  
document.write("<br>Linked List after "
               "Deletion of 2: <br>");
printList(head);
  
// This code is contributed by rag2127
  
</script>


Output

Created Linked List: 
 1  2  3  5  2  10 
Linked List after Deletion of 2: 
 1  2  3  5  10 

Time Complexity: O(n)

Auxiliary Space: O(1)

The above solution doesn’t work when the node to be deleted is the last node.
Following solution handles all cases. 

C++




// A C++ program to demonstrate deletion of last
// Node in singly linked list
#include <bits/stdc++.h>
using namespace std;
  
// A linked list Node
struct Node {
    int data;
    struct Node* next;
};
  
// Function to delete the last occurrence
void deleteLast(struct Node* head, int x)
{
    struct Node *temp = head, *ptr = NULL;
    while (temp) {
  
        // If found key, update
        if (temp->data == x) 
            ptr = temp;        
        temp = temp->next;
    }
  
    // If the last occurrence is the last node
    if (ptr != NULL && ptr->next == NULL) {
        temp = head;
        while (temp->next != ptr) 
            temp = temp->next;       
        temp->next = NULL;
    }
  
    // If it is not the last node
    if (ptr != NULL && ptr->next != NULL) {
        ptr->data = ptr->next->data;
        temp = ptr->next;
        ptr->next = ptr->next->next;
        free(temp);
    }
}
  
/* Utility function to create a new node with
given key */
struct Node* newNode(int x)
{
    Node* node = new Node ;
    node->data = x;
    node->next = NULL;
    return node;
}
   
  
// This function prints contents of linked list
// starting from the given Node
void display(struct Node* head)
{
    struct Node* temp = head;
    if (head == NULL) {
        cout <<"NULL\n";
        return;
    }
    while (temp != NULL) {
        cout <<" --> "<< temp->data;
        temp = temp->next;
    }
    cout <<"NULL\n";
}
  
/* Driver program to test above functions*/
int main()
{
    struct Node* head = newNode(1);
    head->next = newNode(2);
    head->next->next = newNode(3);
    head->next->next->next = newNode(4);
    head->next->next->next->next = newNode(5);
    head->next->next->next->next->next = newNode(4);
    head->next->next->next->next->next->next = newNode(4);
    cout <<"Created Linked list: ";
    display(head);
    deleteLast(head, 4);
    cout <<"Linked List after deletion of 4: ";
    display(head);
    return 0;
}
  
// This code is contributed by shivanisinghss2110


C




// A C program to demonstrate deletion of last
// Node in singly linked list
#include <stdio.h>
#include <stdlib.h>
  
// A linked list Node
struct Node {
    int data;
    struct Node* next;
};
  
// Function to delete the last occurrence
void deleteLast(struct Node* head, int x)
{
    struct Node *temp = head, *ptr = NULL;
    while (temp) {
  
        // If found key, update
        if (temp->data == x) 
            ptr = temp;        
        temp = temp->next;
    }
  
    // If the last occurrence is the last node
    if (ptr != NULL && ptr->next == NULL) {
        temp = head;
        while (temp->next != ptr) 
            temp = temp->next;       
        temp->next = NULL;
    }
  
    // If it is not the last node
    if (ptr != NULL && ptr->next != NULL) {
        ptr->data = ptr->next->data;
        temp = ptr->next;
        ptr->next = ptr->next->next;
        free(temp);
    }
}
  
/* Utility function to create a new node with
given key */
struct Node* newNode(int x)
{
    struct Node* node = malloc(sizeof(struct Node*));
    node->data = x;
    node->next = NULL;
    return node;
}
  
// This function prints contents of linked list
// starting from the given Node
void display(struct Node* head)
{
    struct Node* temp = head;
    if (head == NULL) {
        printf("NULL\n");
        return;
    }
    while (temp != NULL) {
        printf("%d --> ", temp->data);
        temp = temp->next;
    }
    printf("NULL\n");
}
  
/* Driver program to test above functions*/
int main()
{
    struct Node* head = newNode(1);
    head->next = newNode(2);
    head->next->next = newNode(3);
    head->next->next->next = newNode(4);
    head->next->next->next->next = newNode(5);
    head->next->next->next->next->next = newNode(4);
    head->next->next->next->next->next->next = newNode(4);
    printf("Created Linked list: ");
    display(head);
    deleteLast(head, 4);
    printf("List after deletion of 4: ");
    display(head);
    return 0;
}


Java




// Java program to demonstrate deletion of last 
// Node in singly linked list 
class GFG 
{
  
// A linked list Node 
static class Node 
    int data; 
    Node next; 
}; 
  
// Function to delete the last occurrence 
static void deleteLast(Node head, int x) 
    Node temp = head, ptr = null
    while (temp!=null
    
  
        // If found key, update 
        if (temp.data == x) 
            ptr = temp;     
        temp = temp.next; 
    
  
    // If the last occurrence is the last node 
    if (ptr != null && ptr.next == null
    
        temp = head; 
        while (temp.next != ptr) 
            temp = temp.next; 
        temp.next = null
    
  
    // If it is not the last node 
    if (ptr != null && ptr.next != null)
    
        ptr.data = ptr.next.data; 
        temp = ptr.next; 
        ptr.next = ptr.next.next; 
        System.gc();
    
  
/* Utility function to create a new node with 
given key */
static Node newNode(int x) 
    Node node = new Node(); 
    node.data = x; 
    node.next = null
    return node; 
  
// This function prints contents of linked list 
// starting from the given Node 
static void display(Node head) 
    Node temp = head; 
    if (head == null
    
        System.out.print("null\n"); 
        return
    
    while (temp != null
    
        System.out.printf("%d --> ", temp.data); 
        temp = temp.next; 
    
    System.out.print("null\n"); 
  
/* Driver code*/
public static void main(String[] args) 
{
    Node head = newNode(1); 
    head.next = newNode(2); 
    head.next.next = newNode(3); 
    head.next.next.next = newNode(4); 
    head.next.next.next.next = newNode(5); 
    head.next.next.next.next.next = newNode(4); 
    head.next.next.next.next.next.next = newNode(4); 
    System.out.print("Created Linked list: "); 
    display(head); 
    deleteLast(head, 4); 
    System.out.print("List after deletion of 4: "); 
    display(head); 
}
}
  
/* This code is contributed by PrinciRaj1992 */


Python3




# A Python3 program to demonstrate deletion of last
# Node in singly linked list
  
# A linked list Node
class Node: 
    def __init__(self, new_data): 
        self.data = new_data 
        self.next = None
  
# Function to delete the last occurrence
def deleteLast(head, x):
  
    temp = head
    ptr = None
    while (temp!=None): 
  
        # If found key, update
        if (temp.data == x) :
            ptr = temp     
        temp = temp.next
      
    # If the last occurrence is the last node
    if (ptr != None and ptr.next == None): 
        temp = head
        while (temp.next != ptr) :
            temp = temp.next    
        temp.next = None
      
    # If it is not the last node
    if (ptr != None and ptr.next != None): 
        ptr.data = ptr.next.data
        temp = ptr.next
        ptr.next = ptr.next.next
          
    return head
      
# Utility function to create a new node with
# given key 
def newNode(x):
  
    node = Node(0)
    node.data = x
    node.next = None
    return node
  
# This function prints contents of linked list
# starting from the given Node
def display( head):
  
    temp = head
    if (head == None): 
        print("None\n")
        return
      
    while (temp != None): 
        print( temp.data," -> ",end="")
        temp = temp.next
      
    print("None")
  
# Driver code
  
head = newNode(1)
head.next = newNode(2)
head.next.next = newNode(3)
head.next.next.next = newNode(4)
head.next.next.next.next = newNode(5)
head.next.next.next.next.next = newNode(4)
head.next.next.next.next.next.next = newNode(4)
print("Created Linked list: ")
display(head)
head = deleteLast(head, 4)
print("List after deletion of 4: ")
display(head)
  
# This code is contributed by Arnab Kundu


C#




// C# program to demonstrate deletion of last 
// Node in singly linked list 
using System;
  
class GFG 
{
  
// A linked list Node 
public class Node 
    public int data; 
    public Node next; 
}; 
  
// Function to delete the last occurrence 
static void deleteLast(Node head, int x) 
    Node temp = head, ptr = null
    while (temp != null
    
  
        // If found key, update 
        if (temp.data == x) 
            ptr = temp;     
        temp = temp.next; 
    
  
    // If the last occurrence is the last node 
    if (ptr != null && ptr.next == null
    
        temp = head; 
        while (temp.next != ptr) 
            temp = temp.next; 
        temp.next = null
    
  
    // If it is not the last node 
    if (ptr != null && ptr.next != null)
    
        ptr.data = ptr.next.data; 
        temp = ptr.next; 
        ptr.next = ptr.next.next; 
    
  
/* Utility function to create a new node with 
given key */
static Node newNode(int x) 
    Node node = new Node(); 
    node.data = x; 
    node.next = null
    return node; 
  
// This function prints contents of linked list 
// starting from the given Node 
static void display(Node head) 
    Node temp = head; 
    if (head == null
    
        Console.Write("null\n"); 
        return
    
    while (temp != null
    
        Console.Write("{0} --> ", temp.data); 
        temp = temp.next; 
    
    Console.Write("null\n"); 
  
/* Driver code*/
public static void Main(String[] args) 
{
    Node head = newNode(1); 
    head.next = newNode(2); 
    head.next.next = newNode(3); 
    head.next.next.next = newNode(4); 
    head.next.next.next.next = newNode(5); 
    head.next.next.next.next.next = newNode(4); 
    head.next.next.next.next.next.next = newNode(4); 
    Console.Write("Created Linked list: "); 
    display(head); 
    deleteLast(head, 4); 
    Console.Write("List after deletion of 4: "); 
    display(head); 
}
}
  
// This code contributed by Rajput-Ji


Javascript




<script>
  
// JavaScript program to demonstrate
// deletion of last 
// Node in singly linked list     
  
// A linked list Node
class Node {
    constructor() {
        this.data = 0;
        this.next = null;
    }
}
  
    // Function to delete the last occurrence
    function deleteLast(head , x) {
       var temp = head, ptr = null;
        while (temp != null) {
  
            // If found key, update
            if (temp.data == x)
                ptr = temp;
            temp = temp.next;
        }
  
        // If the last occurrence is the last node
        if (ptr != null && ptr.next == null) {
            temp = head;
            while (temp.next != ptr)
                temp = temp.next;
            temp.next = null;
        }
  
        // If it is not the last node
        if (ptr != null && ptr.next != null) {
            ptr.data = ptr.next.data;
            temp = ptr.next;
            ptr.next = ptr.next.next;
          
        }
    }
  
    /*
     Utility function to create a new
     node with given key
     */
    function newNode(x) {
       var node = new Node();
        node.data = x;
        node.next = null;
        return node;
    }
  
    // This function prints contents of linked list
    // starting from the given Node
    function display(head) {
        var temp = head;
        if (head == null) {
            document.write("null<br/>");
            return;
        }
        while (temp != null) {
            document.write( temp.data + " --> ");
            temp = temp.next;
        }
        document.write("null<br/>");
    }
  
    /* Driver code */
      
        var head = newNode(1);
        head.next = newNode(2);
        head.next.next = newNode(3);
        head.next.next.next = newNode(4);
        head.next.next.next.next = newNode(5);
        head.next.next.next.next.next = newNode(4);
        head.next.next.next.next.next.next = newNode(4);
        document.write("Created Linked list: ");
        display(head);
        deleteLast(head, 4);
        document.write("List after deletion of 4: ");
        display(head);
  
// This code contributed by gauravrajput1 
  
</script>


Output

Created Linked list:  --> 1 --> 2 --> 3 --> 4 --> 5 --> 4 --> 4NULL
Linked List after deletion of 4:  --> 1 --> 2 --> 3 --> 4 --> 5 --> 4NULL

Time Complexity: O(n)

Auxiliary Space: O(1)

 



Last Updated : 10 Jan, 2023
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