First time here? Checkout the FAQ!
+3 votes

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)   | 2.5k 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??
in selection sort=n
in insertion sort =0

3 Answers

+8 votes
Best answer
(C) Selection sort
answered by Boss (6.2k 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 May 2017
  1. akash.dinkar12

    3146 Points

  2. pawan kumarln

    1608 Points

  3. sh!va

    1580 Points

  4. Arjun

    1326 Points

  5. Devshree Dubey

    1230 Points

  6. Angkit

    1028 Points

  7. Debashish Deka

    1012 Points

  8. Bikram

    970 Points

  9. LeenSharma

    810 Points

  10. srestha

    662 Points

Monthly Topper: Rs. 500 gift card
Top Users 2017 May 22 - 28
  1. pawan kumarln

    234 Points

  2. Ahwan

    118 Points

  3. jjayantamahata

    106 Points

  4. joshi_nitish

    106 Points

  5. Aditya GN

    63 Points

22,722 questions
29,048 answers
27,510 users