Example: FindSecondSmallest_Sorting in Java

// FindSecondSmallest_Sorting
import java.util.Arrays;

public class Main {
    public static int findSecondSmallestUsingSort(int[] arr) {
        if (arr == null || arr.length < 2) {
            System.out.println("Array must contain at least two elements.");
            return -1; // Indicate error or invalid input
        }

        // Step 1: Sort the array
        Arrays.sort(arr);

        // Step 2: Iterate to find the second distinct smallest element
        // The smallest element is at arr[0].
        // We look for the first element greater than arr[0].
        for (int i = 1; i < arr.length; i++) {
            if (arr[i] > arr[0]) {
                return arr[i]; // This is the second smallest distinct element
            }
        }
        
        // If all elements are the same (e.g., [5, 5, 5]),
        // there is no distinct second smallest element.
        System.out.println("No distinct second smallest element found.");
        return -1;
    }

    public static void main(String[] args) {
        int[] arr1 = {12, 5, 2, 10, 8, 2, 1};
        System.out.println("Original array: " + Arrays.toString(arr1));
        System.out.println("Second smallest element (Sorting): " + findSecondSmallestUsingSort(arr1)); // Output: 5

        int[] arr2 = {7, 7, 3, 3, 5};
        System.out.println("Original array: " + Arrays.toString(arr2));
        System.out.println("Second smallest element (Sorting): " + findSecondSmallestUsingSort(arr2)); // Output: 5

        int[] arr3 = {10, 10, 10, 10};
        System.out.println("Original array: " + Arrays.toString(arr3));
        System.out.println("Second smallest element (Sorting): " + findSecondSmallestUsingSort(arr3)); // Output: -1

        int[] arr4 = {5};
        System.out.println("Original array: " + Arrays.toString(arr4));
        System.out.println("Second smallest element (Sorting): " + findSecondSmallestUsingSort(arr4)); // Output: -1
    }
}