Example: FindNthElementsIterative in Java

// FindNthElementsIterative
import java.util.Arrays;

public class Main {
    public static void main(String[] args) {
        int[] numbers = {10, 5, 20, 8, 15, 20, 12, 5};
        System.out.println("Original array: " + Arrays.toString(numbers));

        // Step 1: Handle edge cases for array size
        if (numbers.length < 2) {
            System.out.println("Array must have at least 2 elements to find second smallest.");
            return;
        }
        if (numbers.length < 3) {
            System.out.println("Array must have at least 3 elements to find third largest.");
            return;
        }

        // --- Find Second Smallest Element ---
        // Initialize firstSmallest and secondSmallest to maximum possible integer value
        int firstSmallest = Integer.MAX_VALUE;
        int secondSmallest = Integer.MAX_VALUE;

        // Step 2: Iterate through the array to find the second smallest
        for (int num : numbers) {
            if (num < firstSmallest) {
                // If current number is smaller than firstSmallest, update both
                secondSmallest = firstSmallest;
                firstSmallest = num;
            } else if (num < secondSmallest && num != firstSmallest) {
                // If current number is smaller than secondSmallest but not equal to firstSmallest, update secondSmallest
                secondSmallest = num;
            }
        }

        // --- Find Third Largest Element ---
        // Initialize largest1, largest2, and largest3 to minimum possible integer value
        int largest1 = Integer.MIN_VALUE;
        int largest2 = Integer.MIN_VALUE;
        int largest3 = Integer.MIN_VALUE;

        // Step 3: Iterate through the array to find the third largest
        for (int num : numbers) {
            if (num > largest1) {
                // If current number is greater than largest1, shift all down
                largest3 = largest2;
                largest2 = largest1;
                largest1 = num;
            } else if (num > largest2 && num != largest1) {
                // If current number is greater than largest2 but not equal to largest1
                largest3 = largest2;
                largest2 = num;
            } else if (num > largest3 && num != largest2 && num != largest1) {
                // If current number is greater than largest3 but not equal to largest1 or largest2
                largest3 = num;
            }
        }

        System.out.println("Second Smallest Element: " + secondSmallest);
        System.out.println("Third Largest Element: " + largest3);
    }
}