I was wondering how to find the previous node in a singly, circular linked list.
In this picture I have 4 nodes.
http://i.imgur.com/hlvzT.png
If I wanted to get rid of the node Sarah, I would have to save it in a temporary struct before I removed it so I wouldn't lose the address of Dave. But how would I access the node David so I could assign the address of Dave into it?
I was wondering how to find the previous node in a singly, circular linked list.
you probably need to go full circle to find out what it is.
well it didn't work out the way i had hoped. I'll just ask my professor.
Last edited by november1992; 09-21-2012 at 06:07 PM.
You can keep track of the previous node,by having an extra pointer named prevOriginally Posted by november1992
That would be easier, but it was supposed to be singly linked not doubly.
In the snippet below, curr and prev are pointer to the nodes.
Code:curr = prev = 0x250; /* pointer to Sarah */ do prev = prev->next; while (prev->next != curr); /* find prev */ /* curr now points to Sarah; prev points to David; curr->next points to Dave */ prev->next = curr->next; /* get Sarah off the list */ free(curr); /* release resources for Sarah */
Last edited by qny; 09-22-2012 at 03:17 AM. Reason: added what curr->next points to
Don't forget to reset any remaining dangling pointers!
Then you can't get to the previous node without starting from some node earlier in the list and traversing up to the desired node.
While it's great that you will or did go and ask your professor, and in fact we sometimes have to push people to do so, primarily when the requirements are unclear; there is no reason to think that they know any better than some of the better programmers on here. In fact the knowledge on here is generally a lot more up-to-date.
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