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.

C++

// C++ Program to find decimal value of
// binary linked list
#include <bits/stdc++.h>
using namespace std;

/* Link list Node */
class Node
{
    public:
    bool data;
    Node* next;
};

/* Returns decimal value of binary linked list */
int decimalValue(Node *head)
{
    // Initialized result
    int res = 0;

    // Traverse linked list
    while (head != NULL)
    {
        // Multiply result by 2 and add
        // head's data
        res = (res << 1) + head->data;

        // Move next
        head = head->next;
    }
    return res;
}

// Utility function to create a new node.
Node *newNode(bool data)
{
    Node *temp = new Node;
    temp->data = data;
    temp->next = NULL;
    return temp;
}

/* Driver program to test above function*/
int main()
{
    /* Start with the empty list */
    Node* head = newNode(1);
    head->next = newNode(0);
    head->next->next = newNode(1);
    head->next->next->next = newNode(1);

    cout << "Decimal value is "
        << decimalValue(head);

    return 0;
}

// This is code is contributed by rathbhupendra

C

// C Program to find decimal value of
// binary linked list
#include<iostream>
using namespace std;

/* Link list Node */
struct Node
{
    bool data;
    struct Node* next;
};

/* Returns decimal value of binary linked list */
int decimalValue(struct Node *head)
{
    // Initialized result
    int  res = 0;

    // Traverse linked list
    while (head != NULL)
    {
        // Multiply result by 2 and add
        // head's data
        res = (res  << 1) + head->data;

        // Move next
        head = head->next;
    }
    return res;
}

// Utility function to create a new node.
Node *newNode(bool data)
{
    struct Node *temp = new Node;
    temp->data = data;
    temp->next = NULL;
    return temp;
}

/* Driver program to test above function*/
int main()
{
    /* Start with the empty list */
    struct Node* head = newNode(1);
    head->next = newNode(0);
    head->next->next = newNode(1);
    head->next->next->next = newNode(1);

    cout << "Decimal value is "
         << decimalValue(head);

    return 0;
}

Java

// Java Program to find decimal value of
// binary linked list
class GFG
{

// Link list Node /
static class Node
{
    boolean data;
    Node next;
};

// Returns decimal value of binary linked list /
static int decimalValue( Node head)
{
    // Initialized result
    int res = 0;

    // Traverse linked list
    while (head != null)
    {
        // Multiply result by 2 and add
        // head's data
        res = (res << 1) + (head.data?1:0);

        // Move next
        head = head.next;
    }
    return res;
}

// Utility function to create a new node.
static Node newNode(int data)
{
    Node temp = new Node();
    temp.data = (data==1? true:false);
    temp.next = null;
    return temp;
}

// Driver code/
public static void main(String args[])
{
    // Start with the empty list /
    Node head = newNode(1);
    head.next = newNode(0);
    head.next.next = newNode(1);
    head.next.next.next = newNode(1);

    System.out.print( "Decimal value is "+decimalValue(head));
}
}

// This code is contributed by Arnab Kundu

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

C#

// C# Program to find decimal value of
// binary linked list
using System;

class GFG
{

// Link list Node /
public class Node
{
    public Boolean data;
    public Node next;
};

// Returns decimal value of binary linked list
static int decimalValue( Node head)
{
    // Initialized result
    int res = 0;

    // Traverse linked list
    while (head != null)
    {
        // Multiply result by 2 and add
        // head's data
        res = (res << 1) + (head.data ? 1 : 0);

        // Move next
        head = head.next;
    }
    return res;
}

// Utility function to create a new node.
static Node newNode(int data)
{
    Node temp = new Node();
    temp.data = (data == 1 ? true : false);
    temp.next = null;
    return temp;
}

// Driver code
public static void Main(String []args)
{
    // Start with the empty list
    Node head = newNode(1);
    head.next = newNode(0);
    head.next.next = newNode(1);
    head.next.next.next = newNode(1);

    Console.WriteLine("Decimal value is " +
                       decimalValue(head));
}
}

// This code is contributed by Rajput-Ji

Javascript

<script>

// Javascript Program to find decimal value of
// binary linked list
// Link list Node /
     class Node {
         constructor(){
         this.data = true;
         this.next = null;
    }
    }

    // Returns decimal value of binary linked list /
    function decimalValue(head) {
        // Initialized result
        var res = 0;

        // Traverse linked list
        while (head != null) {
            // Multiply result by 2 and add
            // head's data
            res = (res << 1) + (head.data ? 1 : 0);

            // Move next
            head = head.next;
        }
        return res;
    }

    // Utility function to create a new node.
    function newNode(data) {
var temp = new Node();
        temp.data = (data == 1 ? true : false);
        temp.next = null;
        return temp;
    }

    // Driver code/

        // Start with the empty list /
var head = newNode(1);
        head.next = newNode(0);
        head.next.next = newNode(1);
        head.next.next.next = newNode(1);

        document.write("Decimal value is "
        + decimalValue(head));

// This code contributed by aashish1995

</script>

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.

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