C 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.

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 code
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;
}

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!