Linked Lists
Below is a small figure that shows a linked list with 4 nodes. Please show the necessary steps to insert a node after the 2nd element in the list.
head tail end
5 8 2 7
next --->next ---->next ---->next--------end
end--prev<--- prev<---- prev <---- prev
You may use auxiliary variables of type nodePtr (a pointer to a node structure), if you need.
Also, if a linked list was circular (i.e., the [I]prev[I] pointer in the first element was pointing to the last element in the list - and the [I]next[I] pointer of the last element points to the first element in the list), how would you be able to find out if you've reached the end of the list if you are traversing it (in order to avoid going around the list forever)
allocate memory for a new node,adjust the next pointer to point to the third element,and adjust the prev pointer to point to the second element
adjust the next pointer of the second element to point to this new element and adjust the previous pointer of the original third element to point to this new added element.
thats one way of doing it.
Last edited by qqqqxxxx; 03-09-2006 at 11:13 PM.
and if a list was circular,there is no first element then ,is there?
qqqqxxxx, so how would the code look to adjust the next pointer to point to the second element,and adjust the prev pointer to point to the first element
adjust the next pointer of the first element to point to this new element and adjust the previous pointer of the original 2nd element to point to this new added element.
On if a cicular linked list, well I would think that it would last forever too so thanks for the check!
you'll get better responses if you post the code you're having trouble with.
Code:#include <cmath> #include <complex> bool euler_flip(bool value) { return std::pow ( std::complex<float>(std::exp(1.0)), std::complex<float>(0, 1) * std::complex<float>(std::atan(1.0) *(1 << (value + 2))) ).real() < 0; }
assuming q is the address of the first node then,
q->next->next
is the address of the second node.
and so on,Code:struct node *n = (struct node *)malloc(sizeof(struct node)); struct node *temp =q->next->next; n->prev= temp; //adjusting the new element (third)to n->next= temp->next; // point to the right places temp->next =n; //adjusting the 2nd element
can u complete the rest of the code?
Alternatively u could have an addnode function.
Last edited by qqqqxxxx; 03-09-2006 at 11:51 PM.
Alright i got it now, thanks
