Find the decimal number from the linked list representation of its binary form !

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Input: head = [1,0,1]
Output: 5
Explanation: (101) in base 2 = (5) in base 10
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode() : val(0), next(nullptr) {}
 *     ListNode(int x) : val(x), next(nullptr) {}
 *     ListNode(int x, ListNode *next) : val(x), next(next) {}
 * };
 */
class Solution
{
public:
    void rev(ListNode *head, vector<int> &v)
    {
        if (head == 0)
            return;
        else
            rev(head->next, v);
        v.push_back(head->val);
    }
    int getDecimalValue(ListNode *head)
    {
        vector<int> v;
        rev(head, v);
        int sum = 0, i = 1;
        for (auto it : v)
        {
            if (it == 1)
            {
                sum += i;
            }
            i *= 2;
        }
        return sum;
    }
};

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