Python Program To Find Decimal Equivalent Of Binary Linked List

Given a singly linked list of 0s and 1s find its decimal equivalent.

Input: 0->0->0->1->1->0->0->1->0
Output: 50   

Input: 1->0->0
Output: 4

The decimal value of an empty linked list is considered as 0.

Initialize the result as 0. Traverse the linked list and for each node, multiply the result by 2 and add the node’s data to it.

Python3

# Python3 program to find decimal value
# of binary linked list

# Node Class
class Node:

    # Function to initialise the
    # node object
    def __init__(self, data):

        # Assign data
        self.data = data

        # Initialize next as null
        self.next = None

# Linked List class contains
# a Node object
class LinkedList:

    # Function to initialize head
    def __init__(self):

        self.head = None

    # Returns decimal value of binary
    # linked list
    def decimalValue(self, head):

        # Initialized result
        res = 0

        # Traverse linked list
        while head:

            # Multiply result by 2 and
            # add head's data
            res = (res << 1) + head.data

            # Move Next
            head = head.next

        return res

# Driver code
if __name__ == '__main__':

    # Start with the empty list
    llist = LinkedList()

    llist.head = Node(1)
    llist.head.next = Node(0)
    llist.head.next.next = Node(1)
    llist.head.next.next.next = Node(1)
    print("Decimal Value is {}".format(
           llist.decimalValue(llist.head)))
# This code is contributed by Mohit Jangra

Output :

Decimal value is 11

Time Complexity: O(n) where n is the number of nodes in the given linked list.
Auxiliary Space: O(1), no extra space is required, so it is a constant.

Please refer complete article on Decimal Equivalent of Binary Linked List for more details!