First time here? Checkout the FAQ!
+1 vote
Why space complexity of heapsort is O(1)....and why not O(logn)..because of space required by recursion calls which is equivalent to height of the tree...where am i getting wrong plz help...
asked in Algorithms by (259 points)   | 222 views
I think auxillary space required will be O(1) but no total space complexity,not sure.

2 Answers

0 votes
answered by Boss (5.5k points)  
I have already seen this answer. But I am still not getting why space required by recursion calls is not considered.
very nice question. i have the same doubt.. It should be log n because every time we are calling  heapify on the root of tree?  experts advice needed...............
0 votes

HEAP SORT uses MAX_HEAPIFY function which calls itself but it can be made using a simple while loop and thus making it an iterative function which inturn takes no space and hence Space Complexity of HEAP SORT can be reduced to O(1).

while ( i < = heapsize) {
 lc <- left(i)
 rc <- right(i)
 if (lc<=heapsize) and (A[lc]>A[i])
  largest <- lc
  largest <- i 
 if (rc<=heapsize) and (A[rc]>A[largest])
  largest <- rc
 if (largest != i)
   exchange A[i] <-> A[largest]
   i <- largest
answered by (21 points)  
Top Users Feb 2017
  1. Arjun

    5274 Points

  2. Bikram

    4230 Points

  3. Habibkhan

    3842 Points

  4. Aboveallplayer

    3086 Points

  5. Debashish Deka

    2378 Points

  6. sriv_shubham

    2308 Points

  7. Smriti012

    2236 Points

  8. Arnabi

    2008 Points

  9. sh!va

    1672 Points

  10. mcjoshi

    1640 Points

Monthly Topper: Rs. 500 gift card

20,845 questions
26,001 answers
22,093 users