Convert Binary Number in a Linked List to Integer.cpp

/*
1290. Convert Binary Number in a Linked List to Integer

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

*/

class Solution {
public:
    int getDecimalValue(ListNode* head) {
        int ans=0;
        ListNode* temp=head;
        while(temp!=NULL){
            ans*=2;
            ans+=(temp->val);
            temp=temp->next;
        }
        return ans;
    }
};