hmmm i already realised that and even mailed that before :) and if we want to use constant space do not make an array. the bst itself is good enough to do what we are doing.
On 5/14/10, anna thomas <annathoma...@gmail.com> wrote: > @rohit: Divya's soltn works in this way, if the sum of 2 nos is less than > req sum, increment the 1st ptr(ptr at beginning of array). If sum > req sum, > then decrement the 2nd ptr(ptr at end of array) > In ur example: ptr1 pts to 1 and ptr2 to 123456 (sum > 6) > dec ptr2 1+4 = 5 (sum < 6) > inc ptr2: 2+4 =6 (got the ans) > > But the qs mentions that it should be in O(1) space. > Regards, > Anna > > > > 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. >> > > -- > 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. > > -- -------------------------------------------------- Rohit Saraf Second Year Undergraduate, Dept. of Computer Science and Engineering IIT Bombay http://www.cse.iitb.ac.in/~rohitfeb14 -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. 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