This can be done using the concept of median of medians, wherein we can achieve linear time complexity in the worst case. This is a concept used in parallel algorithms too, check it out.
On Mon, Jun 18, 2012 at 5:38 PM, Prem Nagarajan <[email protected]>wrote: > @enchantress : This problem can be solved using quicksort in O(nlogn). No > need to go for selection sort. > But O(n) solution is needed. > > > On Mon, Jun 18, 2012 at 2:50 PM, enchantress <[email protected]>wrote: > >> >> Hi all, >> A variation of selection sort can be used which takes O(nk) time. >> >> for i 1 to k >> min_index = i >> for j i+1 to n >> if a[j] < a[min_index] >> min_index = j >> swap(a[i],a[min_index]) >> >> required element : a[k] >> >> On Sunday, 17 June 2012 08:13:18 UTC+5:30, Prem Nagarajan wrote: >> >>> Give an array of unsorted elements, find the kth smallest element in the >>> array. >>> >>> The expected time complexity is O(n) and no extra memory space should be >>> used. >>> >>> Quickselect algorithm can be used to obtain the solution. Can anyone >>> explain how quickselect works? >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Algorithm Geeks" group. >> To view this discussion on the web visit >> https://groups.google.com/d/msg/algogeeks/-/FABBRabzVqMJ. >> >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> 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 [email protected]. > To unsubscribe from this group, send email to > [email protected]. > 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 [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
