import java.util.*;

public class SlicesExample {
    public static void main(String[] args) {
        List<String> s = null;
        System.out.println("uninit: " + s + " " + (s == null) + " " + (s != null && s.size() == 0));

        // To create an empty slice with non-zero length, use the ArrayList constructor.
        s = new ArrayList<>(Arrays.asList(new String[3]));
        System.out.println("emp: " + s + " len: " + s.size() + " cap: " + ((ArrayList<String>) s).size());

        // We can set and get just like with arrays.
        s.set(0, "a");
        s.set(1, "b");
        s.set(2, "c");
        System.out.println("set: " + s);
        System.out.println("get: " + s.get(2));
        System.out.println("len: " + s.size());

        // In addition to these basic operations, slices support several more that make them richer than arrays.
        s.add("d");
        s.addAll(Arrays.asList("e", "f"));
        System.out.println("apd: " + s);

        // Slices can also be copied.
        List<String> c = new ArrayList<>(s);
        System.out.println("cpy: " + c);

        // Slices support a “slice” operator with the syntax list.subList(low, high).
        List<String> l = s.subList(2, 5);
        System.out.println("sl1: " + l);

        // This slices up to (but excluding) s[5].
        l = s.subList(0, 5);
        System.out.println("sl2: " + l);

        // And this slices up from (and including) s[2].
        l = s.subList(2, s.size());
        System.out.println("sl3: " + l);

        // We can declare and initialize a variable for slice in a single line as well.
        List<String> t = Arrays.asList("g", "h", "i");
        System.out.println("dcl: " + t);

        // The Collections utility class contains a number of useful utility functions for slices.
        List<String> t2 = Arrays.asList("g", "h", "i");
        if (t.equals(t2)) {
            System.out.println("t == t2");
        }

        // Slices can be composed into multi-dimensional data structures. The length of the inner slices can vary, unlike with multi-dimensional arrays.
        List<List<Integer>> twoD = new ArrayList<>();
        for (int i = 0; i < 3; i++) {
            List<Integer> innerList = new ArrayList<>();
            for (int j = 0; j <= i; j++) {
                innerList.add(i + j);
            }
            twoD.add(innerList);
        }
        System.out.println("2d: " + twoD);
    }
}