Apr 8, 2017 · Why is the best case time complexity for selection sort O(n^2) when it is O(n) for insertion sort and bubble sort? Their average times are same. I don't understand why the best case times are different. Would appreciate some help.

Jan 20, 2022 · Your code hase the same complexity O(n^2) as usual selection sort, you just fill sorted items from the end rather than from start. There are n-1 loops with run lengths n,n-1, n-2..1 , so sum of arithmetic progression gives about n*(n-1)/2 comparisons and n exchanges.

Oct 31, 2023 · Although Time Complexity of selection sort and insertion sort is the same, that is n(n - 1)/2. The average performance insertion sort is better. Tested on my i5 cpu with random 30000 integers, selection sort took 1.5s in average, while insertion sort take 0.6s in average.

Finding time complexity is often described in a way that is not really very helpful. Here is how it works for Selection Sort. passes The very first time through the algorithm, you must scan all n elements of the data. The very next time through (on recursion), you must scan all but one, which is (n-1). And so on.

Apr 20, 2016 · The time complexity for selection sort is O(n^2). It is same for worst best and average cases. You should have look at the link below it gives a good rundown on selection sort.

Jun 3, 2019 · Possible duplicate of Best case time complexity for selection sort – 17slim. Commented Jun 3, 2019 at 15:46.

Aug 29, 2024 · So with selection sort there is no concept of worst case, best case: all cases are equal. Analysis. The two (nested) loops in selection sort are really visiting all possible pairs of (𝑖, 𝑗), where 0 ≤ 𝑖 < 𝑗 < 𝑛. So the inner if statement is executed as many times as there are such pairs (𝑖, 𝑗).

The easiest way to compute the time complexity is to model the time complexity of each function with a separate recurrence relation. We can model the time complexity of the function smallest with the recurrence relation S(n) = S(n-1)+O(1), S(1)=O(1). This obviously solves to S(n)=O(n).

Jan 9, 2012 · Thanks for your answer. If we make assumption that we always make 50/50 split. That should give us O(nlogn), this is mentioned in the wikipedia page: "Note the resemblance to quicksort: just as the minimum-based selection algorithm is a partial selection sort, this is a partial quicksort, generating and partitioning only O(log n) of its O(n) partitions".

Mar 12, 2020 · The selection sort algorithm iteratively searches for the minimum remaining element and swaps it into place. This doesn't create an opportunity to detect that the array is already in increasing order, so there's no opportunity to terminate early, and selection sort's best case running time is therefore Θ(n 2).