SortingAlgorithms.java

import java.util.Scanner;

public class SortingAlgorithms {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.println("Choose sorting algorithm:");
        System.out.println("1. Insertion Sort");
        System.out.println("2. Selection Sort");
        System.out.print("Enter your choice (1 or 2): ");
        
        int choice = scanner.nextInt();
        
        System.out.println("\nEnter the number of elements: ");
        int n = scanner.nextInt();
        int[] arr = new int[n];
        
        System.out.println("\nEnter the elements: ");
        for (int i = 0; i < n; i++) {
            System.out.print("Enter element " + (i + 1) + ": ");
            arr[i] = scanner.nextInt();
        }
        
        System.out.println("\nArray before sorting: ");
        printArray(arr);
        System.out.println();
        
        if (choice == 1) {
            insertionSort(arr);
        } else if (choice == 2) {
            selectionSort(arr);
        }
        
        System.out.println("\nArray after sorting: ");
        printArray(arr);
        
        scanner.close();
    }
    
    // Insertion Sort
    private static void insertionSort(int[] arr) {
        for (int i = 1; i < arr.length; i++) {
            int j = i;
            while (j > 0 && arr[j-1] > arr[j]) {
                int temp = arr[j];
                arr[j] = arr[j-1];
                arr[j-1] = temp;
                j = j-1;
            }
            
            System.out.println("Insertion Sort - Array after pass " + i + ": ");
            printArray(arr);
            System.out.println();
        }
    }
    
    // Selection Sort
    private static void selectionSort(int[] arr) {
        for(int i = 0; i < arr.length; i++) {
            int smallest = arr[i];
            int smallestIndex = i;
            for(int j = i; j < arr.length; j++) {
                if (arr[j] < smallest) {
                    smallest = arr[j];
                    smallestIndex = j;
                }
            }
            int temp = smallest;
            arr[smallestIndex] = arr[i];
            arr[i] = temp;
            
            System.out.println("Selection Sort - Array after pass " + (i+1) + ": ");
            printArray(arr);
            System.out.println();
        }
    }
    
    // Helper method to print array
    private static void printArray(int[] arr) {
        for (int i = 0; i < arr.length; i++) {
            System.out.print(arr[i]);
            if (i < arr.length - 1) {
                System.out.print(" | ");
            }
        }
        System.out.println();
    }
}