Insertion Sort in a sentence

Algorithm for insertion sort A graphical example of insertion sort.

For example, since the run-time of insertion sort grows quadratically as its input size increases, insertion sort can be said to be of order O(n 2 ).

If the input array is already sorted, insertion sort performs as few as n-1 comparisons, thus making insertion sort more efficient when given sorted or "nearly sorted" arrays.

Insertion sort main Insertion sort is a simple sorting algorithm that is relatively efficient for small lists and mostly sorted lists, and is often used as part of more sophisticated algorithms.

List insertion sort is a variant of insertion sort.

Insertion sort is widely used for small data sets, while for large data sets an asymptotically efficient sort is used, primarily heap sort, merge sort, or quicksort.

A good implementation of Insertion sort is fast for small arrays, stable, in-place, and can significantly speed up Radix Sort.

A hybrid sorting approach, such as using insertion sort for small bins improves performance of radix sort significantly.

Assuming the k+1st element's rank is random, insertion sort will on average require shifting half of the previous k elements, while selection sort always requires scanning all unplaced elements.

A useful optimization in practice for the recursive algorithms is to switch to insertion sort or selection sort for "small enough" sublists.

However, insertion sort or selection sort are both typically faster for small arrays (i.e. fewer than 10–20 elements).

In general, insertion sort will write to the array O(n 2 ) times, whereas selection sort will write only O( n ) times.

It can be seen as an advantage for some real-time applications that selection sort will perform identically regardless of the order of the array, while insertion sort's running time can vary considerably.

It improves upon bubble sort and insertion sort by moving out of order elements more than one position at a time.

Shell sort (see below) is a variant of insertion sort that is more efficient for larger lists.

Simple sorts Two of the simplest sorts are insertion sort and selection sort, both of which are efficient on small data, due to low overhead, but not efficient on large data.

So for unsorted input, insertion sort will usually perform about half as many comparisons as selection sort.

While insertion sort typically makes fewer comparisons than selection sort, it requires more writes because the inner loop can require shifting large sections of the sorted portion of the array.

Best, worst, and average cases Animation of the insertion sort sorting a 30 element array.

Binary insertion sort employs a binary search to determine the correct location to insert new elements, and therefore performs ⌈log 2 (n)⌉ comparisons in the worst case, which is O(n log n).