*np *is nothing but *next_pointer. np[x] *does mean *x->np *which is the next pointer to node. Actually I am thinking in this way about *np, *that it stores the *XOR* value of *next* and *prev* pointers.Or Since *np *is a k-bit integer, the first k/2 bits wil be used for *next*, and other k/2 bits wil be used for *prev *pointer.
On Wednesday, 20 June 2012 18:28:07 UTC+5:30, adarsh kumar wrote: > > Simple! > Just traverse the doubly linked list and keep track of next and previous > of each node, and do XOR and save the result in a new pointer, what > according to you is "np". > Be careful about boundary cases, i.e head and tail, though. > > On Wed, Jun 20, 2012 at 5:16 PM, Krishna Kishore <kknarenkris...@gmail.com > > wrote: > >> Explain how to implement doubly linked lists using only one pointer value >> * np[x*] per item instead of the usual two (next and prev). Assume that >> all pointer values can be interpreted as >> k-bit integers, and define* np[x] to be np[x] = next[x] XOR prev[x],*the >> k-bit “exclusive-or” of next[x] and prev[x]. (The value NIL is >> represented by 0.) Be sure to describe what information is needed to >> access the head of the list. Show how to implement the SEARCH, INSERT, and >> DELETE operations on such a list. Also show how to reverse such a list in >> O(1) time. >> >> This is the Question in the Book "*Introduction To Algorithms" *By >> CORMEN ( MIT Press ) Page Number : 209 , Problem No: 10.2-8. >> >> Thanks in Advance. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Algorithm Geeks" group. >> To view this discussion on the web visit >> https://groups.google.com/d/msg/algogeeks/-/Uj1E8KXljAQJ. >> To post to this group, send email to algogeeks@googlegroups.com. >> To unsubscribe from this group, send email to >> algogeeks+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/algogeeks?hl=en. >> > > -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To view this discussion on the web visit https://groups.google.com/d/msg/algogeeks/-/JlNBCRsj9kUJ. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
