Dummy Interview Problems

DummyInterview001.java

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import java.util.*;

/**
 * Dummy Interview 1: Sorting
 * --------------------------
 *
 * Given an array of integers, pls provide a way to print all the numbers that the count of digits equals n.
 * And for every digit it is under ascending order from left to right.
 *
 * e.g. n = 3, print 123, 124, 125, ..., 189
 *
 * -------------------------------
 * Created by au9ustine on 1/1/14.
 */
public class DummyInterview001 {

    private int i = 0;
    private List<Integer> vec = new ArrayList<Integer>();
    private int k = 0;
    private PriorityQueue<Integer> q = new PriorityQueue<Integer>();
    private Integer[] expected;

    @Before
    public void prepare() throws InterruptedException {
        // suite initialization
        q.clear();

        // expected data preparation
        LinkedList<Integer> jlist = new LinkedList<Integer>();
        for (int j = 123; j < 189; j++) {
            jlist.add(j);
        }
        expected = jlist.toArray(new Integer[0]);

        // vec and k init
        int j = 0;
        while (j < expected.length) {
            Random random = new Random(System.currentTimeMillis());
            int some = expected[random.nextInt(expected.length)];
            if (vec.contains(some) != true) {
                vec.add(some);
                j++;
            }
        }
        k = vec.size();
    }

    @Test
    public void testSort() {
        for (i = 0; i < k; i++) {
            q.add(vec.get(i));
        }
        int vec_index = 0;
        while (i < vec.size()) {
            vec.set(vec_index++, q.poll());
            q.add(vec.get(i++));
        }
        while (q.size() > 0) {
            vec.set(vec_index++, q.poll());
        }
        Assert.assertArrayEquals(expected, vec.toArray(new Integer[0]));
    }
}