What is the average case complexity of selection sort

Hence, the worst case has:. The best case is the case when the array is already sorted. This is the best case as we can avoid the swap at each step but the time spend to find the smallest element is still O N.

Hence, the best case has:. Based on the worst case and best case, we know that the number of comparisons will be the same for every case and hence, for average case as well, the number of comparisons will be constant. Hence, the average case has:. Hence, in terms of Space Complexity, Selection Sort is optimal as the memory requirements remain same for every input.

As a summary,. Up Get FREE domain for 1st year and build your brand new site In this article, you will learn about Time Complexity and Space Complexity of Selection Sort algorithm along with the complete mathematical analysis of the different cases. In Selection Sort, we maintain two parts: Sorted sub-array Unsorted sub-array In sorted sub-array, all elements are in sorted order and are less than all elements of the unsorted sub-array.

Worst Case Time Complexity of Selection Sort The worst case is the case when the array is already sorted with one swap but the smallest element is the last element. Worst Case: a2, a3, Among the comparison based techniques discussed, only Insertion Sort qualifies for this because of the underlying algorithm it uses i. Out of comparison based techniques, bubble sort, insertion sort and merge sort are stable techniques. Selection sort is unstable as it may change the order of elements with the same value.

For example, consider the array 4, 4, 1, 3. In the first iteration, the minimum element found is 1 and it is swapped with 4 at 0th position. Therefore, the order of 4 with respect to 4 at the 1st position will change. Similarly, quick sort and heap sort are also unstable.

Out of non-comparison based techniques, Counting sort and Bucket sort are stable sorting techniques whereas radix sort stability depends on the underlying algorithm used for sorting. Analysis of sorting techniques :. Que — 1. Which sorting algorithm will take the least time when all elements of input array are identical?

Consider typical implementations of sorting algorithms. Que — 2. Consider the Quicksort algorithm. Suppose there is a procedure for finding a pivot element which splits the list into two sub-lists each of which contains at least one-fifth of the elements. C Programs. C - Arrays and Pointers. C - Stacks and Queues.

C - Linked Lists. C - Matrices. Discussion Forum. What is the average case complexity of selection sort? O nlogn b. O logn c. Confused About the Answer? Ask for Details Here Know Explanation?