I am not sure if constant space requirement is possible. But we can do it with O(k) space complexity. Maintain a max heap of k elements. For each of the n*m sums add it to the heap (if it ain't full with k elements) or replace the root and heapify if the sum is lesser than the root.
Finally the root will have the k'th smallest sum. But this would require O(n*m*log k) time complexity. On Sat, Sep 5, 2009 at 5:10 AM, ankur aggarwal <ankur.mast....@gmail.com>wrote: > @dufus.. > if there is constant space requirement then ?? > wat will be your soln ?? > > > On Sat, Sep 5, 2009 at 12:35 PM, Dufus <rahul.dev.si...@gmail.com> wrote: > >> >> It seems EXTRACT_MIN for Z[n^2] can be done in O(n) time. >> http://lyle.smu.edu/~saad/courses/cse3358/ps5/problemset5sol.pdf<http://lyle.smu.edu/%7Esaad/courses/cse3358/ps5/problemset5sol.pdf> >> >> Then using it we can find the kth smallest element in O(nk) time. >> >> _dufus >> >> >> On Sep 4, 10:03 pm, ankur aggarwal <ankur.mast....@gmail.com> wrote: >> > Find nth smallest inO(n) Given two arrays of length n in sorted order >> > X[n] & Y[n]. >> > Now make another array Z[n^2]={such that z belongs to X+Y}. >> > AS all possible sum of x+y is there in Z. You have to give the nth >> smallest >> > no of Z in O(n) time. >> > Space complexity : No bound on it. But try to optimize it if possible. >> >> >> > > > > -- Yesterday is History. Tomorrow is a Mystery. Today is a Gift! That is why it is called the Present :). http://sites.google.com/site/ramaswamyr --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. 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 -~----------~----~----~----~------~----~------~--~---
