1290. Convert Binary Number in a Linked List to Integer

https://leetcode.com/problems/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.

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

Example 3:

**Input:** head = [1]

**Output:** 1

Example 4:

**Input:** head = [1,0,0,1,0,0,1,1,1,0,0,0,0,0,0]

**Output:** 18880

Example 5:

**Input:** head = [0,0]

**Output:** 0

Constraints:

• The Linked List is not empty.

• Number of nodes will not exceed 30.

• Each node's value is either 0 or 1.

ac