LeetCode - Convert Binary Number in a Linked List to Integer - GoldmanSachs - Easy - C+++

int getDecimalValue(ListNode* head) {
        int kow = 0;
        while(head != NULL){
            kow *= 2;
            if(head -> val == 1){
                kow += 1;
            }
            head = head -> next;
        }
        return kow;
    }