Dot Product Calculation Link List Implementation - c++

Question

I am trying to implement the a dot product calculation formula into the linked list implementation on my below code and I am having the below error:
request for member 'add_node' in 'B', which is of pointer type 'linked_list {aka node*}' (maybe you meant to use '->' ?)
How can I clear that and make working code? I don't want to use classes as well
#include <iostream>
#include <stdlib.h>
using namespace std;
struct node
{
int data;
int index;
node *next;
};
typedef node* linked_list;
node *head = NULL;
node *tail = NULL;
void add_node(int i,int n)
{
node *tmp = new node;
tmp->index = i;
tmp->data = n;
tmp->next = NULL;
if(head == NULL)
{
head = tmp;
tail = tmp;
}
else
{
tail->next = tmp;
tail = tail->next;
}
}
void display(node *head)
{
while(head!=0)
{
cout << head->index <<" ," << head->data << endl;
display(head->next);
break;
}
}
int main()
{
linked_list A;
A.add_node(2,7);
A.add_node(4,5);
A.add_node(7,8);
A.add_node(9,4);
linked_list B;
B.add_node(3,5);
B.add_node(4,6);
B.add_node(9,5);
int product=0;
while(A!=0 && B!=0)
{
if(A->index == B->index)
{
product = product + A->data * B->data;
A=A->next;
B=B->next;
}
else if(A->index < B->index)
{
A=A->next;
}
else
{
B=B->next;
}
}
return product;
return 0;
}

Answer 1

The error tells you what you need to know. linked_list is a pointer. You need to use the -> operator, not the dot operator.
Additionally, your node struct does not contain a method called add_node(). In fact it doesn't contain any methods at all.

Answer 2

#include <iostream>
using namespace std;
struct node
{
int data;
int index;
node *next;
};
class linked_list
{
private:
node *head,*tail;
public:
linked_list()
{
head = NULL;
tail = NULL;
}
void add_node(int i,int n)
{
node *tmp = new node;
tmp->index = i;
tmp->data = n;
tmp->next = NULL;
if(head == NULL)
{
head = tmp;
tail = tmp;
}
else
{
tail->next = tmp;
tail = tail->next;
}
}
node* gethead()
{
return head;
}
};
void display(node *head)
{
while(head!=0)
{
cout << head->index <<" ," << head->data << endl;
display(head->next);
break;
}
}
int main()
{
linked_list A;
A.add_node(2,7);
A.add_node(4,5);
A.add_node(7,8);
A.add_node(9,4);
linked_list B;
B.add_node(3,5);
B.add_node(4,6);
B.add_node(9,5);
display(A.gethead());
display(B.gethead());
int product=0;
node *current_a = A.gethead();
node *current_b = B.gethead();
while(current_a != 0 && current_b!=0)
{
if(current_a->index == current_b->index)
{
product = product + current_a->data * current_b->data;
current_a=current_a->next;
current_b=current_b->next;
}
else if(current_a->index < current_b->index)
{
current_a=current_a->next;
}
else
{
current_b=current_b->next;
}
}
cout<<"\nDot Product : "<< product<<endl;
return 0;
}
enter code here