Python Program For Deleting Last Occurrence Of An Item From Linked List

# Python program to implement 
# the above approach
# 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")
        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

# 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("Linked List after Deletion of 1: ") 
    printList(head) 
# This code is contributed by Arnab Kundu

# 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")
        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