1. CSC 205 Java Programming II
Lecture 27
March 20, 2002

2. Instance Variable VeryLongInt CLASS
THE ONLY FIELD WILL BE:
ArrayList digits; // holds all of the digits
// in the VeryLongInteger

3. Default Constructor public VeryLongInt( ) {
final int INITIAL_CAPACITY = 500;
digits= new ArrayList (INITIAL_CAPACITY);
} // default constructor

4. Constructor With String Param.
FOR THE CONSTRUCTOR WITH A STRING PARAMETER:
FOR EACH CHARACTER c IN s,
MAKE SURE ‘0’ <= c <= ‘9’
IF SO, APPEND (c – ‘0’) TO digits.

5. Constructor With String Param.
public VeryLongInt (String s) {
// for each character, if the character is between // ‘0’ and ‘9’, convert the character to a digit and
// append the digit to digits.
} // constructor with string parameter
Suppose s = “3x79”. What will digits contain?

6. The toString Method public String toString() {
final String EMPTY_STRING = "";
String s = EMPTY_STRING;
for (int i = 0; i < digits.size(); i++)
s += digits.get (i);
return s;
} // method toString

7. The add Method VeryLongInt a1, a2; // a1 = {3, 8, 7, 4, 9, 7}
FOR THE add METHOD:
VeryLongInt a1,
a2;
// a1 = {3, 8, 7, 4, 9, 7}
// a2 = {5, 3, 8, 4}
a1.add (a2);

8. The add Method public void add (VeryLongInt otherVeryLong) {
  final int BASE = 10;
  int largerSize, partialSum, carry = 0;
VeryLongInt sum = new VeryLongInt();
if (digits.size() > otherVeryLong.digits.size())
largerSize = digits.size();
else
largerSize = otherVeryLong.digits.size();

9. The add Method partialSum = least (i) +
for (int i = 0; i < largerSize; i++) {
  partialSum = least (i) +
otherVeryLong.least (i) + carry;
carry = partialSum / BASE;
sum.digits.add (new Integer (
partialSum % BASE));
} // for
  if (carry == 1)
sum.digits.add (new Integer (carry));
Collections.reverse (sum.digits);
digits = sum.digits;
} // method add

10. The least Method Suppose the VeryLongInt object has the value 13579
then
least (0) RETURNS 9
least (1) RETURNS 7
least (2) RETURNS 5
least (3) RETURNS 3
least (4) RETURNS 1
least (5) RETURNS 0
least (6) RETURNS 0
...

11. The Deck Class public class Deck {
final static public int MAX_NUMBER =
Card.getNumberOfSuits()*Card.getNumberOfRanks();
private ArrayList cards;
public Deck() {
cards = new ArrayList(MAX_NUMBER);
for (int i = 0; i < 4; i++)
for (int j = 0; j < 13; j++)
cards.add(new Card(j, i)); }

12. The Hand Class public class Hand { private int cardsRemained;
ArrayList[] suits;
public Hand() {
suits = new ArrayList[4];
for (int i=0; i<SUITS; i++)
suits[i] = new ArrayList();
cardsRemained = 0; }