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.
Example 1:
Input: head = [1,0,1] Output: 5 Explanation: (101) in base 2 = (5) in base 10
Example 2:
Input: head = [0] Output: 0
Constraints:
- The Linked List is not empty.
- Number of nodes will not exceed
30. - Each node's value is either
0or1.
