Selection Sort

Selection Sort (Brute Force) — Sorting by repeated selection.

Sorting technique:

• Find smallest element and put in first place
• Find next smallest element and put in second place
• Repeat till end of list

Pseudocode:

Javacode:

package sorting;

public class SelectionSort {

    public int[] sort(int[] array){
        System.out.println("Starting sort");
        int length = array.length;
        for (int i = 0; i < length; i++) {
            int minvalue = array[i];
            int minindex = i;
            for (int j = i+1; j < length; j++) {
                if (array[j] < minvalue) {
                    minvalue = array[j];
                    minindex = j;
                }
            }
            swap(array, i, minindex);
        }
        return array;
    }

    private void swap (int[] array, int i, int j) {
        int tmp = array[i];
        array[i] = array[j];
        array[j] = tmp;
    }

}

Asymptotic analysis

Theta(n) = n squared

O(n) = n squared

Note: Please “follow” and leave a “clap” :-)