Question

In python, Give an algorithm for finding the second-to-last node in a singly linked

list in which the last node is indicated by a next reference of None.

Answer 1

class Node: 
    def __init__(self, data): 
        self.data = data 
        self.next = None

n1 = Node(1)
n2 = Node(2)
n3 = Node(3)
n4 = Node(4)
n5 = Node(5)

n1.next = n2
n2.next = n3
n3.next = n4
n4.next = n5

temp = n1

prev = None
while temp.next != None:
    prev = temp
    temp = temp.next

print(prev.data)

Code :

Output :