Example: FindSecondSmallestAndLargest_SinglePass in Java

// FindSecondSmallestAndLargest_SinglePass
public class Main {
    public static void main(String[] args) {
        int[] arr = {10, 5, 20, 15, 25, 5}; // Example array

        // Step 1: Handle edge cases
        if (arr.length < 2) {
            System.out.println("Array must contain at least two elements.");
            return;
        }

        // Step 2: Initialize variables for smallest and largest elements
        int smallest = Integer.MAX_VALUE;
        int secondSmallest = Integer.MAX_VALUE;
        int largest = Integer.MIN_VALUE;
        int secondLargest = Integer.MIN_VALUE;

        // Step 3: Iterate through the array once
        for (int num : arr) {
            // Logic for smallest and second smallest
            if (num < smallest) {
                secondSmallest = smallest; // Current smallest becomes second smallest
                smallest = num;            // Current num becomes new smallest
            } else if (num < secondSmallest && num != smallest) {
                secondSmallest = num;      // Update second smallest if num is between smallest and secondSmallest
            }

            // Logic for largest and second largest
            if (num > largest) {
                secondLargest = largest;   // Current largest becomes second largest
                largest = num;             // Current num becomes new largest
            } else if (num > secondLargest && num != largest) {
                secondLargest = num;       // Update second largest if num is between largest and secondLargest
            }
        }

        // Step 4: Print the results
        if (secondSmallest == Integer.MAX_VALUE) {
            System.out.println("No distinct second smallest element found.");
        } else {
            System.out.println("Second Smallest: " + secondSmallest);
        }

        if (secondLargest == Integer.MIN_VALUE) {
            System.out.println("No distinct second largest element found.");
        } else {
            System.out.println("Second Largest: " + secondLargest);
        }
    }
}