Selection Sort Algorithm | Sorting in JAVA

                                                       Sorting in JAVA

2. Selection Sort

Idea: The inner loop selects the minimum element in the unsorted array and places the elements in increasing order. 

Time complexity: O(N2) 

Code

import java.util.*;

 

class Sorting {

   public static void printArray(int arr[]) {

       for(int i=0; i<arr.length; i++) {

           System.out.print(arr[i]+" ");

       }

       System.out.println();

   }

 

   public static void main(String args[]) {

       int arr[] = {7, 8, 1, 3, 2};

 

       //selection sort

       for(int i=0; i<arr.length-1; i++) {

           int smallest = i;

           for(int j=i+1; j<arr.length; j++) {

               if(arr[j] < arr[smallest]) {

                   smallest = j;

               }

           }

           //swap

           int temp = arr[smallest];

           arr[smallest] = arr[i];

           arr[i] = temp;

       }

 

       printArray(arr);

   }

}

Sure! Here's an example implementation of the selection sort algorithm in Java:

java
Copy code
public class SelectionSort {

public static void selectionSort(int[] arr) {
int n = arr.length;

for (int i = 0; i < n-1; i++) {
int minIndex = i;
for (int j = i+1; j < n; j++) {
if (arr[j] < arr[minIndex]) {
minIndex = j;
}
}

// swap the minimum element with the current element
int temp = arr[i];
arr[i] = arr[minIndex];
arr[minIndex] = temp;
}
}

public static void main(String[] args) {
int[] arr = {64, 25, 12, 22, 11};
selectionSort(arr);
for (int i = 0; i < arr.length; i++) {
System.out.print(arr[i] + " ");
}
}
}

In this implementation, the selectionSort() method takes an array of integers as input and sorts the array using the selection sort algorithm. The outer loop iterates through the array, and the inner loop finds the index of the minimum element in the unsorted part of the array. Once the minimum element is found, it is swapped with the current element being sorted. Finally, the sorted array is printed to the console using a for loop in the main() method.