Insertion sort is a simple sorting algorithm that builds the final sorted array one item at a time by comparisons
. It works similarly to the way you sort playing cards in your hands
. The algorithm iterates through the input data, removing one element at a time, and finds the location it belongs within the sorted list, inserting it there
. It repeats this process until no input elements remain
. Some key characteristics of insertion sort include:
- Simple implementation : Insertion sort can be implemented in a few lines of code
- Efficient for small data sets : It is efficient for small data sets, but less efficient on large lists than more advanced algorithms like quicksort, heapsort, or merge sort
- Adaptive : Insertion sort is adaptive, meaning it is efficient for data sets that are already partially sorted
- In-place sorting : Yes, insertion sort is an in-place sorting algorithm
- Stable : Insertion sort is a stable sorting algorithm
The algorithm works as follows:
- Start at the left-most element of the array and invoke Insert to insert each element encountered into its correct position
- At each iteration, remove one element from the input data and find the location it belongs within the sorted list
- Insert the element at the found location
- Repeat until no input elements remain
Insertion sort is particularly useful when the data set is already sorted or when dealing with small data sets
. However, it is less efficient than other sorting algorithms like heap sort, quick sort, and merge sort when dealing with large data sets
