import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.NoSuchElementException;

public class UnsortedMap<K,V> extends AbstractMap<K,V> {
    private ArrayList<Entry<K,V>> entryList;
    
    public UnsortedMap()
    {
	entryList = new ArrayList<>();
    }
    
    @Override
    public int size() {
	return entryList.size();
    }

    @Override
    public void clear() {
	entryList.clear();
    }
    
    private int findKeyIndex(K key)
    {
	int idx=0;
	for (Entry<K,V> e : entryList)
	{
	    if (e.getKey().equals(key))
		return idx;
	    idx++;
	}
	return -1;
    }
    
    @Override
    public boolean containsKey(K key)
    {
	return findKeyIndex(key) >= 0;
    }

    private int findValueIndex(V value)
    {
	int idx=0;
	for (Entry<K,V> e : entryList)
	{
	    if (e.getValue().equals(value))
		return idx;
	    idx++;
	}
	return -1;
    }
    @Override
    public boolean containsValue(V value)
    {
	return findValueIndex(value) >= 0;
    }

    @Override
    public V get(K key)
    {
	int idx = findKeyIndex(key);
	return (idx<0) ? null : entryList.get(idx).getValue();
    }

    @Override
    public V put(K key, V value)
    {
	V v = remove(key);
	entryList.add(new Entry<K,V>(key, value));
	return v;
    }

    @Override
    public V remove(K key)
    {
	int idx = findKeyIndex(key);
	V v=null;
	if (idx>=0)
	{
	    v = entryList.get(idx).getValue();
	    entryList.remove(idx);
	}
	return v;
    }

    private class EntryIterator implements Iterator<MEntry<K,V>>
    {
	int idx=0;
	public boolean hasNext() { return idx<entryList.size(); }	
	public MEntry<K,V> next() { 
	    if (idx>=entryList.size())
		throw new NoSuchElementException(); 
	    return entryList.get(idx++);
	}
	public void remove(K key) { throw new UnsupportedOperationException(); }
    }
    private class EntryIterable implements Iterable<MEntry<K,V>>
    {
	public Iterator<MEntry<K,V>> iterator()  {  return new EntryIterator(); }
    }
    
    @Override
    public Iterable<MEntry<K,V>> entrySet() { return new EntryIterable(); }

    
    public void doExample()    {
	HashMap<Integer, String> m = new HashMap<>();
	System.out.println(m.isEmpty() + " " + m.toString());
	System.out.println(m.put(5,"A") + " " + m.toString());
	System.out.println(m.put(7,"B") + " " + m.toString());
	System.out.println(m.put(2,"E") + " " + m.toString());
	System.out.println(m.put(8,"A") + " " + m.toString());
	System.out.println(m.put(2,"Q") + " " + m.toString());

	System.out.println(m.get(7) + " " + m.toString());
	System.out.println(m.get(4) + " " + m.toString());
	System.out.println(m.remove(2) + " " + m.toString());
	System.out.println(m.remove(5) + " " + m.toString());
	System.out.println(m.isEmpty() + " " + m.toString());
	System.out.println(m.entrySet() + " " + m.toString());
	System.out.println(m.values() + " " + m.toString());
    }

    public static void main(String[] args)
    {
	(new UnsortedMap()).doExample();
    }
}