Which of the following sorting algorithm has best case time complexity of O(n2)?ans.selection sortbubble sortinsertion sortstupid sort Previous Marked for Review Next

All of the sorting algorithms you mentioned - selection sort, bubble sort, insertion sort, and stupid sort - have a best case time complexity of O(n^2).

Here's a brief explanation of each:

1. Selection Sort: This algorithm divides the input into a sorted and an unsorted region. It repeatedly selects the smallest (or largest, depending on the ordering) element from the unsorted region and moves it to the sorted region. Regardless of the input, it has a time complexity of O(n^2).

2. Bubble Sort: This algorithm repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order. The pass through the list is repeated until the list is sorted. The best case time complexity (when the input is already sorted) is O(n), but the average and worst case time complexity is O(n^2).

3. Insertion Sort: This algorithm builds a sorted output one item at a time. It is much less efficient on large lists than more advanced algorithms such as quicksort, heapsort, or merge sort. However, insertion sort provides several advantages: simple implementation, efficient for (quite) small data sets, adaptive, stable, and in-place. The best case time complexity (when the input is already sorted) is O(n), but the average and worst case time complexity is O(n^2).

4. Stupid Sort (also known as Bogosort): This is a highly inefficient sorting algorithm based on the generate and test paradigm. The algorithm successively generates permutations of its input until it finds one that is sorted. It is not useful for sorting, but may be used for educational purposes, to contrast it with more efficient algorithms. Its best case time complexity is O(n), but this is highly unlikely. The average and worst case time complexity is O((n+1)!), which is even worse than O(n^2).

So, all of these algorithms have a best case time complexity of O(n^2), except when the input is already sorted. In that case, bubble sort and insertion sort have a best case time complexity of O(n), and stupid sort has a best case time complexity of O(n), but this is highly unlikely.