import java.io.*;

class Table7 implements Table
{
// Table class, data stored in hash table
// Handles collisions with separate chaining

 private Cell[] array;
 final static int SIZE=41;

 public Table7()
 {
  array = new Cell[SIZE];
 }

 public boolean delete(String key)
 {
  int hash = hash(key);
  if(array[hash]==null)
     return false;
  else if(array[hash].first.equalKey(key))
     {
      array[hash]=array[hash].next;
      return true;
     }
  else
     {
      Cell ptr;
      for(ptr=array[hash];
          ptr!=null&&!(ptr.next.first.equalKey(key));
          ptr=ptr.next);
      if(ptr==null)
         return false;
      else
         {
          ptr.next = ptr.next.next;
          return true;
         }
     }
     
 }

 public void add(KeyObject obj)
 {
  int hash = hash(obj.getKey());
  array[hash] = new Cell(obj,array[hash]);
 }

 public KeyObject retrieve(String key)
 {
  int hash = hash(key);
  if(array[hash]==null)
     return null;
  else
     {
      Cell ptr;
      for(ptr=array[hash]; 
          ptr!=null&&!ptr.first.equalKey(key);
          ptr=ptr.next);
      if(ptr==null)
         return null;
      else
         return ptr.first;
     }
 }

 public void print(PrintStream out)
 {
  for(int i=0;i<SIZE;i++)
     for(Cell ptr=array[i]; ptr!=null; ptr=ptr.next)
        out.println(ptr.first);
 }

 public void printTable()
 {
  for(int i=0;i<SIZE;i++)
     if(array[i]==null)
        System.out.println("---");
     else
        {
         for(Cell ptr=array[i]; ptr!=null; ptr=ptr.next)
            System.out.print(ptr.first.getKey()+"  ");
         System.out.println();
        }
 }

 private static int hash(String key)
 {
  int val=0;
  key = key.toLowerCase();
  for(int i=0; i<key.length(); i++)
     if(Character.isLetter(key.charAt(i)))
        val=(val*32+key.charAt(i)-'a')%SIZE;
  return val;
 }

 private static class Cell
 {
  KeyObject first;
  Cell next;

  Cell(KeyObject f, Cell n)
  {
   first=f;
   next=n;
  } 
 }
}