CPSC 215 Lab 11, 12/2/99

			Multi-Key Hashing

  For this lab you are to implement a hash table containing records of
students, which include their names and phone extensions:


class student
{ String name;          // name of student
  int ssn;		// social security number
  int ext;		// phone extension
  String year;  // e.g, "junior", "senior"...
  String Address = "some tiny dorm room";
  String hobbies = "party all night, go to class late";

  student nextStudent;  // this effectively implements a linked list.
  			// if null (default), then no more records
  
student(String n, int s, String y)  
   { name = n;  ssn = s; year = y;}  // other info entered later

  void printrecord() {}  //you define it

} // end class student


The hash table should be searchable by giving the name, the SSN,
or BOTH.  That is, you need two hash functions:

  h1:  hash the name by taking the adjusted ascii value of the second
       letter of the name string:

  int h1(String name) { return ( (int) name.charAt(1) ) - 65; }

  
  h2:  hash the social security number by taking the last two digits

  int h2(int ssn) { return (ssn % 100); }  // make this % 50 if memory low

  Then you need to creat, for the table, a 2D array of linked lists.
Each list represents all the student records whose names and SSNs
yield the same hash values.  For example, if student "Gary" has SSN
876213422 and student "Mary" has SSN 399515622, then both student
records are to be found in the list of students stored at array
coordinate [32][22], because h1("Gary") == h1("Mary") == 32, and
h2(876213422) == h2(399515622) == 22.

  The dimensions of your array should be 100 by 60, due to the
nature of the hash functions.  


  Your program should create several sample student records, INCLUDING
records that will yield the same hash values.  You need to demonstrate
that your program can search for a record by the name, the SSN, and by
using both.  Define a printrecord method inside class student so you
can demonstrate that your program works correctly.

  Basically, your program should have at minimum the following methods:

  void insert(student s) // inserts new student record into table

  Student lookup(String name)  // looks up the (first) record of a student
			       // of that name

  Student lookup(int ssn)      // looks up record of student who has ssn
			       // as his/her SSN number. 

  Student lookup(String name, int ssn) // lookup using both keys

// These record should report "no such student" if the record can't be found.


 
/* Since I'm a REALLY NICE professor, I won't make you do deletion this time */