[Algorithm] Linked List to Integer (Tree/C++)

Problem Link: https://binarysearch.com/problems/Linked-List-to-Integer

This question is to transform the given linked list representing the binary number into a decimal number. For example, 1->0->0 represents 4 in decimal. This is quite a simple question. Starting from the head node, we track of the res and multiply it by 2 and add the current value.

Linked List to Integer