Space Complexity: Space complexity is O(1) because an extra variable temp is used. So iterations take O (n) time. However it can be made stable. Selection Sort is slower than Insertion Sort, which is why it is rarely used in practice. Bucket Sort To Sort an Array with Negative Numbers, C/C++ Program for Odd-Even Sort / Brick Sort, Java Program for Odd-Even Sort / Brick Sort, Insertion sort to sort even and odd positioned elements in different orders, Count Inversions in an array | Set 1 (Using Merge Sort), k largest(or smallest) elements in an array | added Min Heap method, Write Interview Here, size=5. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready. Selection sort is faster than Bubble sort. Don’t stop learning now. Selection Sort Time Complexity. Time Complexity: O(n 2) Space Complexity: O(1) Input − The unsorted list: 5 9 7 23 78 20 Output − Array after Sorting: 5 7 9 20 23 78 Algorithm selectionSort(array, size) Input: An array of data, and the total number in the array. Space Complexity. Analyzing the time it takes for an algorithm to give output is of crucial importance. 2) Remaining subarray which is unsorted. One of the simplest techniques is a selection sort. In selection sort, the sorted and unsorted array doesn’t make any difference and consumes an order of n 2 (O(n 2)) in both best and worst case complexity. Similarly, it continues to sort the given elements. (Where n is a number of elements in the array (array size).). Stability : The default implementation is not stable. Selection sort uses minimum number of swap operations O(n) among all the sorting algorithms. To gain better understanding about Selection Sort Algorithm. Selection sort is one of the easiest approaches to sorting. Time Complexity: O(n2) as there are two nested loops. close, link Consider the following elements are to be sorted in ascending order using selection sort-, As a result, sorted elements in ascending order are-, Let A be an array with n elements. The first part is the sorted portion, which is written on the left side in the array. At every pass, the smallest element is chosen and swapped with the leftmost unsorted element. The algorithm maintains two subarrays in a given array. Attention reader! Following example explains the above steps: edit Time Complexity: Time Complexity is defined as the number of times a particular instruction set is executed rather than the total time is taken. The time complexity of the Selection Sort algorithm: If you look at steps 2, 3, 4 and 5 iterates ‘n’ number of times. The complexity of Selection Sort Technique. It is an in-place sorting algorithm because it uses no auxiliary data structures while sorting. Because of this selection sort is a very ineffecient sorting algorithm for large amounts of data, it's sometimes preffered for very small amounts of data such as the example above. Exercise : Selection sort is faster than Bubble sort. Please write to us at contribute@geeksforgeeks.org to report any issue with the above content. acknowledge that you have read and understood our, GATE CS Original Papers and Official Keys, ISRO CS Original Papers and Official Keys, ISRO CS Syllabus for Scientist/Engineer Exam, Time Complexities of all Sorting Algorithms, Program to check if a given number is Lucky (all digits are different), Write a program to add two numbers in base 14, Find square root of number upto given precision using binary search. Other Sorting Algorithms on GeeksforGeeks/GeeksQuiz: Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above. In selection sort, the strategy is to find the smallest number in the array and exchange it with the value in first position of array. Auxiliary Space: O(1) 2. Selection Sort is an easy-to-implement, and in its typical implementation unstable, sorting algorithm with an average, best-case, and worst-case time complexity of O (n²). Also, you will find working examples of selection sort in Python. A useful optimization in practice for the recursive algorithms is to switch to insertion sort or selection sort for "small enough" sublists. It finds the second smallest element (5). By using our site, you code. Then, selection sort algorithm used for sorting is as follows-, Consider the following elements are to be sorted in ascending order-, The above selection sort algorithm works as illustrated below-, The state of array after the loops are finished is as shown-. 1) The subarray which is already sorted… As the working of selection, sort does not depend on the original order of the elements in the array, so there is not much difference between best case and worst case complexity of selection sort. The algorithm performs the maximum number of... Best case – this occurs when the provided list is already sorted. The time complexity of selection sort is O(n 2), for best, average, and worst case scenarios. The algorithm maintains two subarrays in a given array. Efficiency of an algorithm depends on two parameters: 1. Selection Sort is slower than Insertion Sort, which is why it is rarely used in practice.