@dufus
if extracting the kth smallest element would tske O(kn) then extracing the
nth element would take O(n^2) right?


On 9/14/09, Ramaswamy R <ramaswam...@gmail.com> wrote:
>
> 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
>
>
> >
>

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