//ActivityConflictDemo.java

public class ActivityConflictDemo
{
    public static void main(String[] args)
    {
        Activity activity1 = new Activity("History museum tour", 9, 10);
        Activity activity2 = new Activity("Morning mountain hike", 9, 12);
        Activity activity3 = new Activity("Boat tour", 11, 14);

        Activity[] activityPairs =
        {
            activity1, activity2,
            activity1, activity3,
            activity2, activity3
        };

        for (int i = 0; i < activityPairs.length; i += 2)
        {
            System.out.printf
            (
                "%s conflicts with %s: %s%n",
                activityPairs[i].name,
                activityPairs[i + 1].name,
                activityPairs[i].conflictsWith(activityPairs[i + 1])
                ? "true" : "false"
            );
        }
    }
}