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/*
* Modification History
*
* 2002-May-25 Jason Rohrer
* Created.
* Made getZero static.
*/
#ifndef BIG_INT_INCLUDED
#define BIG_INT_INCLUDED
/**
* A multi-byte integer representation.
*
* Some of the ideas used in this class were gleaned
* from studying Sun's Java 1.3 BigInteger implementation.
*
* @author Jason Rohrer.
*/
class BigInt {
public:
/**
* Constructs an integer.
*
* @param inSign the sign of this integer:
* -1 if negative, +1 if positive, and 0 if zero.
* @param inNumBytes the number of bytes in this integer.
* @param inBytes the bytes for this integer.
* Copied internally, so must be destroyed by caller.
*/
BigInt( int inSign, int inNumBytes, unsigned char *inBytes );
/**
* Constructs an integer from a 32-bit int.
*
* @param inInt the int to use.
*/
BigInt( int inInt );
~BigInt();
/**
* Adds an integer to this integer.
*
* @praram inOtherInt the int to add.
* Must be destroyed by caller.
*
* @return a newly allocated integer containing the sum.
* Must be destroyed by caller.
*/
BigInt *add( BigInt *inOtherInt );
/**
* Subtracts an integer from this integer.
*
* @praram inOtherInt the int to subtract.
* Must be destroyed by caller.
*
* @return a newly allocated integer containing the difference.
* Must be destroyed by caller.
*/
BigInt *subtract( BigInt *inOtherInt );
/**
* Gets whether this integer is less than another integer.
*
* @praram inOtherInt the integer test.
* Must be destroyed by caller.
*
* @return true if this integer is less than the other.
*/
char isLessThan( BigInt *inOtherInt );
/**
* Gets whether this integer is equal to another integer.
*
* @praram inOtherInt the integer test.
* Must be destroyed by caller.
*
* @return true if this integer is equal to the other.
*/
char isEqualTo( BigInt *inOtherInt );
/**
* Gets a copy of this integer.
*
* @return a newly allocated integer containing the copy.
* Must be destroyed by caller.
*/
BigInt *copy();
/**
* Gets an integer equal to zero.
*
* @return a newly allocated integer containing zero.
* Must be destroyed by caller.
*/
static BigInt *getZero();
/**
* Converts this integer to a decimal string.
*
* @return a \0-terminated ascii decimal string.
* Must be destroyed by caller.
*/
//char *convertToDecimalString();
/**
* Converts this integer to a hex string.
*
* @return a \0-terminated ascii hexx string.
* Must be destroyed by caller.
*/
char *convertToHexString();
/**
* Converts this integer to a 32-bit int.
*
* If this integer contains more than 32-bits, the high-order
* bits will be discarded, though the sign will be preserved.
*/
int convertToInt();
/**
* -1 if negative, +1 if positive, and 0 if zero.
*/
int mSign;
int mNumBytes;
/**
* Integer is stored in big endian byte order.
*/
unsigned char *mBytes;
protected:
/**
* Flips the byte order of this integer.
*
* @return a newly allocated integer containing the flipped version.
* Must be destroyed by caller.
*/
BigInt *flipByteOrder();
/**
* Computes the hex representation of a four-bit int.
*
* @param inInt the four-bit int to convert.
*
* @return the int as a hex ascii character,
* in {0, 1, ..., A, B, ..., F}.
*/
char fourBitIntToHex( int inInt );
};
#endif
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