Weekday or Weekend (Switch Expression)

/*
 * Problem : Process one line of text.
 * Input   : One line of text.
 * Output  : Weekday, Weekend or Invalid.
 * Approach: Switch on the day.
 * Time    : O(1)
 * Space   : O(1)
 * 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(String s) {
        // Step 1: Make the day lower case, so Monday, MONDAY and monday are the same.
        String day = s.trim().toLowerCase();

        // Step 2: Old style switch statement. Every case needs a break, or the next case also runs.
        String result;
        switch (day) {
            case "monday":
            case "tuesday":
            case "wednesday":
            case "thursday":
            case "friday":
                result = "Weekday";
                break;
            case "saturday":
            case "sunday":
                result = "Weekend";
                break;
            default:
                result = "Invalid";
                break;
        }
        return result;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String s = scanner.hasNextLine() ? scanner.nextLine() : "";
        System.out.println(solve(s));
    }
}