Convert Binary Number in a Linked List to Integer

Description

• Given head which is a reference node to a singly-linked list. The value of each node in the linked list is either 0 or 1. The linked list holds the binary representation of a number.

Return the decimal value of the number in the linked list.

The most significant bit is at the head of the linked list.

Constraints

• The Linked List is not empty.
• Number of nodes will not exceed 30.
• Each node's value is either 0 or 1.

Test Cases

• Input: head = [1,0,1]
  Output: 5

• Input: head = [0]
  Output: 0

Code