in starting we keep track of head pointer.. we are having three pointers head,slower,faster, know we start traversing the list if(faster==head||faster->next==head) return slower else faster=faster->next->next slower=slower->next
On Sun, Mar 28, 2010 at 12:15 PM, vikrant singh <vikrantsing...@gmail.com>wrote: > @diamond > sorry but how do we know the fast pointer is pointing to head again? > u see, in case u dont have O(n) space to record visited nodes > > On Sun, Mar 28, 2010 at 10:28 AM, blackDiamond <patidarc...@gmail.com>wrote: > >> vikrant you havent read properly the post by Gaurav when the second >> pointer will come back to the head first will be pointing the middle.(Think >> it)!! >> >> >> On Sun, Mar 28, 2010 at 10:21 AM, vikrant singh <vikrantsing...@gmail.com >> > wrote: >> >>> Well gaurav, i think by this method you can only check for a cycle in the >>> list. >>> If u have any idea how can you implement this to solve originally posted >>> problem? >>> >>> On Sat, Mar 27, 2010 at 9:03 AM, gaurav kishan >>> <gauravkis...@gmail.com>wrote: >>> >>>> Hi, >>>> >>>> Keep two pointers both initially pointing to Head. >>>> Move first pointer one by one and the second pointer by two nodes in >>>> each iteration. >>>> When second pointer next link points to head again,return first pointer. >>>> >>>> Please let me know if this can be further imporved upon or there is some >>>> fallacy in the approach. >>>> >>>> Regards, >>>> Gaurav. >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Algorithm Geeks" group. >>>> To post to this group, send email to algoge...@googlegroups.com. >>>> To unsubscribe from this group, send email to >>>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>>> . >>>> For more options, visit this group at >>>> http://groups.google.com/group/algogeeks?hl=en. >>>> >>> >>> >>> >>> -- >>> Vikrant Singh >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Algorithm Geeks" group. >>> To post to this group, send email to algoge...@googlegroups.com. >>> To unsubscribe from this group, send email to >>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>> . >>> For more options, visit this group at >>> http://groups.google.com/group/algogeeks?hl=en. >>> >> >> >> >> -- >> ~~~~BL/\CK_D!AMOND~~~~~~~~ >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Algorithm Geeks" group. >> To post to this group, send email to algoge...@googlegroups.com. >> To unsubscribe from this group, send email to >> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >> . >> For more options, visit this group at >> http://groups.google.com/group/algogeeks?hl=en. >> > > > > -- > Vikrant Singh > > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to algoge...@googlegroups.com. > To unsubscribe from this group, send email to > algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > -- ~~~~BL/\CK_D!AMOND~~~~~~~~ -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algoge...@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.
