如何找到双向链表的最大元素？

Question

After reading the data from a file in a double-linked list I must determine the maximum of the this data. This topic is new to me so I need some help. This is what i have:

struct node {
  int info;
  node *next, *back;
};
node *cap = NULL;
node *first, *last, *c, *q;

Answer 1

Iterate over the list and store the max like this:

node *max = first;
while (first) {
    if (max->info < first->info)
        max = first;
    first = first->next;
}

This assumes that next is null pointer when the element is the last one.

Answer 2

What are *c and *q for?

Also, if you can already traverse the list, just create a max node and update it while traversing