package mst;
//import checkers.inference.ownership.quals.*;
public class Hashtable
{
  protected HashEntry array[];
  protected int size;

  public Hashtable(int sz)
  {
    size = sz;
    array = new HashEntry[size];
//    for (int i=0; i<size; i++)
//      array[i] = null;
  }

  private int hashMap(Object key)
  {
    return ((key.hashCode() >> 3 ) % size);
  }

  public Object get(Object key)
  {
    int j = hashMap(key);

    HashEntry ent = null;

    for (ent = array[j]; ent != null && ent.key() != key; ent = ent.next());

    if (ent != null) return ent.entry();
    return null;
  }

  public void put(Object key, Object value)
  {
    int j = hashMap(key);
    HashEntry ent = new  /*@RepOwn*/  HashEntry(key, value, array[j]);
    array[j] = ent;
  }

  public void remove(Object key)
  {
    int j = hashMap(key);
    HashEntry ent = array[j];
    if (ent != null && ent.key() == key)
      array[j] = ent.next();
    else {
      HashEntry prev = ent;
      for (ent = ent.next(); ent != null && ent.key() != key;
	   prev = ent, ent = ent.next());
      prev.setNext(ent.next());
    }
  }

}

class HashEntry
{
  private Object key;
  private Object entry;
  private HashEntry next;

  public HashEntry(Object key, Object entry, HashEntry next)
  {
    this.key = key;
    this.entry = entry;
    this.next = next;
  }

  public Object key()
  {
    return key;
  }

  public Object entry()
  {
    return entry;
  }

  public HashEntry next()
  {
    return next;
  }

  public void setNext(HashEntry n)
  {
    next = n;
  }

}
