GATE CSE
First time here? Checkout the FAQ!
x
+3 votes
1.4k views

Which one of the following in place sorting algorithms needs the minimum number of swaps?

  1. Quick sort
  2. Insertion sort
  3. Selection sort
  4. Heap sort
asked in Algorithms by Loyal (4k points)   | 1.4k views
Shouldn't this be Insertion Sort?

As in Insertion Sort, we "technically" don't swap, but shift elements to place the element under consideration in proper place
does swap here means shifting the elements??

3 Answers

+7 votes
Best answer
(C) Selection sort
answered by Boss (6.3k points)  
selected by
+9 votes
Selection sort

because in selection the maximum swaps which can take place are O(n)

because we pick up an element an find the minimum(in case of forward sorting) from the next index till the end of array and than perform the swap

hence O(n) whereas in all other algos the swaps are greater
answered by (299 points)  
Please compare number of swaps in selection sort with other sorting techniques given in above question.
+1 vote
Number of swaps
Quick sort = $\Theta (nlogn)$
Insertion sort =  $\Theta (n^{2})$
Selction sort = no swaps required since we are shifting elements in the array and not swapping
Heap sort =  $\Theta (nlogn)$

Option C
answered by Active (1.6k points)  
in  quick  wont it be n^2 ?


Top Users Apr 2017
  1. akash.dinkar12

    3660 Points

  2. Divya Bharti

    2580 Points

  3. Deepthi_ts

    2040 Points

  4. rude

    1966 Points

  5. Tesla!

    1768 Points

  6. Debashish Deka

    1614 Points

  7. Shubham Sharma 2

    1610 Points

  8. Prashant.

    1492 Points

  9. Arjun

    1472 Points

  10. Arunav Khare

    1464 Points

Monthly Topper: Rs. 500 gift card

22,086 questions
28,062 answers
63,297 comments
24,169 users