use a hash table. Add the frst element in the hash table.
>From second element, check if the diff (sum - element) is present in the hash table or not. On Fri, May 14, 2010 at 4:20 PM, Rohit Saraf <rohit.kumar.sa...@gmail.com>wrote: > @divya : i guess... it wont work. > consider Array {1,2,3,4,123456} > and you want sum 6. > > @prashant: Is it O(n)? > > I guess after converting to array and removing all entries > sum, we should > start with the smallest element > and scan the elements from last till we get some value x which together > with the smallest value sums to < sum. Call this position POS1. > If we get required sum somewhere in the process, cool ! > Else take drop the elements after POS1 and also the smallest element. > Recurse on the remaining. > > > -------------------------------------------------- > Rohit Saraf > Second Year Undergraduate, > Dept. of Computer Science and Engineering > IIT Bombay > http://www.cse.iitb.ac.in/~rohitfeb14<http://www.cse.iitb.ac.in/%7Erohitfeb14> > > > On Fri, May 14, 2010 at 3:51 PM, Prashant K <prashant.r.k...@gmail.com>wrote: > >> i think it can done like this, >> assume we have to find 'x' and 'y' wer s='x'+'y' >> >> 1) select ith node from tree (from beginning to end) >> 2) y= s - " ith number (node)" >> 3) now search for 'y' in BST if we found then there is node such that s= x >> + y; otherwise no.. >> >> -- Prashant Kulkarni >> || Lokaha Samastaha Sukhino Bhavanthu || >> || Sarve Jana Sukhino Bhavanthu || >> >> >> >> On Fri, May 14, 2010 at 2:47 AM, divya jain <sweetdivya....@gmail.com>wrote: >> >>> form a sorted array from inorder traversal of tree. now take to pointers >>> one to the beginning of array and other at the end. now check if the sum of >>> element is greater than reqd sum then increment 1st ptr. if their sum is >>> less than reqd sum then decrement 2nd ptr. if their sum is equal to the reqd >>> sum then this is the ans.. >>> hope it will work.. >>> >>> >>> On 13 May 2010 20:11, jalaj jaiswal <jalaj.jaiswa...@gmail.com> wrote: >>> >>>> given a bst... find two nodes whose sum is equal to a number k ... in >>>> O(n) time and constant space... >>>> >>>> -- >>>> With Regards, >>>> Jalaj Jaiswal >>>> +919026283397 >>>> B.TECH IT >>>> IIIT ALLAHABAD >>>> >>>> -- >>>> 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. >>>> >>> >>> -- >>> 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. >>> >> >> -- >> 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. >> > > -- > 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. > -- Thanks & Regards, - NMN -- 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.