Second Highest Number with Streams

Optional and streams are Java 8 features.

/*
 * Problem : Process an array.
 * Input   : n, then n integers.
 * Output  : The second highest or none.
 * Approach: distinct, sorted, skip.
 * Time    : O(n log n)
 * Space   : O(n)
 * Java    : 8 or newer.
 */
import java.util.Scanner;

public class Main {
    // This method solves the task. It receives the input and returns the answer.
    static String solve(int[] a) {
        // Step 1: distinct removes equal values.
        // Step 2: sorted in reverse order puts the biggest value first.
        // Step 3: skip(1) drops the highest value. findFirst takes the next one, if there is one.
        java.util.Optional<Integer> second = java.util.Arrays.stream(a)
                .boxed()
                .distinct()
                .sorted(java.util.Comparator.reverseOrder())
                .skip(1)
                .findFirst();

        // Step 4: Optional says "maybe there is no value". We print none for an empty Optional.
        return second.isPresent() ? String.valueOf(second.get()) : "none";
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int size = scanner.nextInt();
        int[] a = new int[size];
        for (int i = 0; i < size; i++) {
            a[i] = scanner.nextInt();
        }
        System.out.println(solve(a));
    }
}