Class MyBigInteger

java.lang.Object
  |
  +--MyBigInteger

class MyBigInteger

extends java.lang.Object

implements MyIntegralNumber

A mutable, arbitrary-precision integer. An arithmetic operation on a MyBigInteger never results in overflow or "wrap around"---instead, the sequence of digits expands as necessary to accomodate any increase in the stored value's magnitude. For example,

   MyBigInteger i = new MyBigInteger(65536);

   System.out.println(i);  // 65536
   i = i.squareOf();
   System.out.println(i);  // 4294967296
   i = i.squareOf();
   System.out.println(i);  // 18446744073709551616
   i = i.squareOf();
   System.out.println(i);  // 340282366920938463463374607431768211456
   i = i.squareOf();
   System.out.println(i);  // 115792089237316195423570985008687907853
                           //  269984665640564039457584007913129639936
 
   MyBigInteger j = new MyBigInteger(1);
   j.plus(i);
   System.out.println(j);  // 115792089237316195423570985008687907853
                           //  269984665640564039457584007913129639937

[When they're printed via System.out.println, MyBigIntegers are displayed in decimal, as implied by the specification of toString in MyNumber.]

[In its internal storage, a MyBigInteger is free to use any radix that is convenient.]

Constructor Summary

MyBigInteger(int i)
Constructs a new MyBigInteger object that initially stores the integer value i.

Method Summary

java.lang.Object	clone() Returns a new MyNumber object that initially equals this.
MyNumber	createCompatible(int i) Returns a new MyNumber object that initially holds the value i.
boolean	divides(MyIntegralNumber n) Returns true if n is evenly divisible by this.
boolean	equals(java.lang.Object o) Tests whether o and this are equal.
boolean	lessThan(MyNumber n) Returns true if this is smaller than n.
void	minus() Replaces this with -this.
void	plus(MyNumber n) Replaces this with this + n.
MyNumber	squareOf() Returns a new object holding the square of the value of this.
void	times(MyNumber n) Replaces this with this * n.
java.lang.String	toString() Retrieves the decimal representation of the stored integer.

Methods inherited from class java.lang.Object

, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

MyBigInteger

public MyBigInteger(int i)

Constructs a new MyBigInteger object that initially stores the integer value i.

Parameters:

i - the integer value to initially store in the new object

Method Detail

clone

public java.lang.Object clone()

Description copied from interface: MyNumber

Returns a new MyNumber object that initially equals this.

[The returned object is guaranteed to be an instance of this's class.]

Overrides:

clone in class java.lang.Object

Tags copied from interface: MyNumber

Returns:

a new MyNumber (of the same class as this) that takes this's integer value as its initial stored value

createCompatible

public MyNumber createCompatible(int i)

Description copied from interface: MyNumber

Returns a new MyNumber object that initially holds the value i.

[The returned object is guaranteed to be an instance of this's class.]

Example:

   // construct n...
   MyNumber n   = new MyInteger(3);

   // increment n...
   MyNumber one = n.createCompatible(1);  // ...one is a MyInteger.
   n.plus(one);

[The behavior of the createCompatible method is undefined if i is too large (or too small) to be handled by this's variety of number.]

Tags copied from interface: MyNumber

Returns:

a new MyNumber (of the same class as this) that takes i as its initial stored value

lessThan

public boolean lessThan(MyNumber n)

Description copied from interface: MyNumber

Returns true if this is smaller than n.

[The behavior of the lessThan method is undefined if n is not compatible with this.]

Tags copied from interface: MyNumber

Parameters:

n - the number to compare against this

Returns:

true if this is less than n; false otherwise

equals

public boolean equals(java.lang.Object o)

Description copied from interface: MyNumber

Tests whether o and this are equal.

Overrides:

equals in class java.lang.Object

Tags copied from interface: MyNumber

Parameters:

o - the object to compare against this

Returns:

true if (1) o is a MyNumber that is compatible with this and (2) o and this currently store the same integer value; false otherwise

minus

public void minus()

Description copied from interface: MyNumber

Replaces this with -this.

plus

public void plus(MyNumber n)

Description copied from interface: MyNumber

Replaces this with this + n.

[The behavior of the plus method is undefined if n is not compatible with this.]

Tags copied from interface: MyNumber

Parameters:

n - the number to be added to this

squareOf

public MyNumber squareOf()

Description copied from interface: MyNumber

Returns a new object holding the square of the value of this.

[The returned object is guaranteed to be an instance of this's class.]

Tags copied from interface: MyNumber

Returns:

a new MyNumber object (of the same class as this) that initially stores the square of this object's integer value.

times

public void times(MyNumber n)

Description copied from interface: MyNumber

Replaces this with this * n.

[The behavior of the times method is undefined if n is not compatible with this.]

Tags copied from interface: MyNumber

Parameters:

n - the number by which this is to be scaled

divides

public boolean divides(MyIntegralNumber n)

Description copied from interface: MyIntegralNumber

Returns true if n is evenly divisible by this.

[The divides method's behavior is undefined when this is zero.]

Specified by:

divides in interface MyIntegralNumber

Tags copied from interface: MyIntegralNumber

Parameters:

n - the integral number to divide into

Returns:

true if n is divisible by this; false otherwise

toString

public java.lang.String toString()

Description copied from interface: MyNumber

Retrieves the decimal representation of the stored integer.

Overrides:

toString in class java.lang.Object

Tags copied from interface: MyNumber

Returns:

a String that represents the stored integer, in decimal