public class BagWrapper {

public static interface Bag { public int size(); public boolean isEmpty(); public void add(Object e); public boolean isMember(Object e); public boolean remove(Object e); public int removeAll(Object e); public int count(Object e); public void clear(); public Object[] toArray(); }

public static class DynamicBag implements Bag{

private Object[] elements; private int currentSize; private static final int DEFAULT_SIZE = 10;

public DynamicBag(int initialSize) { if (initialSize < 1) { throw new IllegalArgumentException("Size must be at least 1"); } this.elements = new Object[initialSize]; this.currentSize = 0; }

public DynamicBag() { this(DEFAULT_SIZE); }

@Override public int size() { return this.currentSize; }

@Override public boolean isEmpty() { return this.size() == 0; }

@Override public void add(Object e) { if (e == null) { throw new IllegalArgumentException("Argument cannot be null"); } if (this.size() == this.elements.length) { this.reAllocate(); } this.elements[this.currentSize++] = e; }

private void reAllocate() { Object temp[] = new Object[2*this.size()]; for (int i=0; i < this.size(); ++i) { temp[i] = this.elements[i]; } this.elements = temp; }

@Override public boolean isMember(Object e) { return this.count(e) > 0; }

@Override public boolean remove(Object e) { for (int i=0; i < this.size(); ++i) { if (this.elements[i].equals(e)) { this.elements[i] = this.elements[this.currentSize-1]; this.elements[this.currentSize-1] = null; --this.currentSize; return true; } } return false; }

@Override public int removeAll(Object e) { int result = 0; while(this.remove(e)) { result++; } return result; }

@Override public int count(Object e) { int result = 0; for (int i=0; i < this.size(); ++i) { if (this.elements[i].equals(e)) { result++; } } return result; }

@Override public void clear() { for (int i=0; i < this.size(); ++i) { this.elements[i] = null; } this.currentSize = 0; }

public Object[] toArray() { Object[] result = new Object[this.size()]; for (int i=0; i < this.size(); ++i) { result[i] = this.elements[i]; } return result; }

}

// NON-MEMBER METHOD

public static int bagScaler(Bag B, int n) {

// ADD YOUR CODE HERE

return n; //dummy return } }