DuplicateCheck.java

// Sample input: 1 5 2 5 3 -1 -> not distinct
// Terminate input with a negative integer and return key
import java.util.*;

public class DuplicateCheck {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        boolean isDistinct = true; int num;
        System.out.println("Enter sequence of numbers: ");

        List<Integer> list = new ArrayList<>();
        do {
            num = input.nextInt();
            list.add(num);
        } while (num >= 0);
        input.close();

        Set<Integer> set = new TreeSet<>(list);
        if (set.size() < list.size()) isDistinct = false;

        System.out.println("They are " +(isDistinct ? "" : "not ")+ "distinct" );
        System.out.println("Sorted elements: " + set);
    }
}