linked lists

[danny2785]

Can someone help me understand reversing a singly linked list without recursion?

struct node* result = NULL;
struct node* current = *headRef;
struct node* next;
while (current != NULL) {
next = current->next; // tricky: note the next node
current->next = result; // move the node onto the result
result = current;
current = next;
}


why does this work? Sorry this is probably easy but I just don't understand it conceptually.

 

[xwb]

Try drawing it out. Start with

HeadRef -> A -> B -> C -> D -> NULL

Just work through the code and work out where result, current and next point to on each statement.

 

[cpjust]

Try drawing a picture or diagram of what the code is doing. Once you see a diagram of how it works, it'll probably make more sense.