JAVA ARRAY ASSIGNMENT HELP PLEASE

This week, it is time to practice arrays so that our methods can process millions of items of data, giving our loops and conditions something useful to do. Create a class ArrayProblems and write the following array methods in it. Again, you must use the JUnit test class TestArrayProblems.java to test out your methods.

You have to start the code with "void squeezeLeft(int[] a)" that modifies the contents of its parameter array a by moving all its nonzero elements to the left as far as it can, writing over the zero elements that precede them. For example, if called with the parameter array {0, 1, 0, 0, 3, -2, 0, 7}, the contents of this array after the call would be {1, 3, -2, 7, 0, 0, 0, 0}. (For an extra challenge, you can try make your method work in place so that it doesnt create another array to use as temporary workspace. For an even harder challenge for the truly hardcore among you, make your method work in one pass through the array.)

import static org.junit.Assert.*; import org.junit.After; import org.junit.Before; import org.junit.Test; import java.util.*; public class TestArrayProblems { private static final int SEED = 12345; private static final int RUNS = 100; private static final int SIZE = 100; private ArrayProblems ap = new ArrayProblems(); 

 @Test public void testSqueezeLeft() { Random rng = new Random(SEED); ArrayList al1 = new ArrayList(10 * RUNS); ArrayList al2 = new ArrayList(10 * RUNS); for(int i = 0; i < RUNS; i++) { al1.clear(); al2.clear(); for(int j = 0; j < RUNS; j++) { int d = rng.nextInt(100000) - 50000; if(d == 0) { d = 1; } al1.add(d); int zeros = rng.nextInt(20); for(int k = 0; k < zeros; k++) { al2.add(0); } al2.add(d); } while(al1.size() < al2.size()) { al1.add(0); } int[] a1 = new int[al1.size()]; int[] a2 = new int[al2.size()]; int loc = 0; for(Integer e: al1) { a1[loc++] = e; } loc = 0; for(Integer e: al2) { a2[loc++] = e; } ap.squeezeLeft(a2); assertArrayEquals(a1, a2); } }