ZZQQCC

A C++ library implementing ZZ, an arbitrary-precision integer class.

Overview

ZZ represents integers of arbitrary size. The name is inspired by the blackboard bold ℤ (the set of all integers). Internally, digits are stored in a base-2^(8·sizeof(unsigned int)) positional system using the helper class i_digits.

Files

File	Description
NearNumber/ZZ.h	ZZ class — arbitrary-precision integer
NearNumber/i_digits.h	i_digits helper — digit storage and carry arithmetic
NearNumber/test.cpp	Example / test program
ZZQQCC.sln	Visual Studio solution

Building

Open ZZQQCC.sln in Visual Studio 2019 or later (MSVC v145 toolset, Windows SDK 10.0) and build the ZZQQCC project.

Supported configurations: Debug|Win32, Release|Win32, Debug|x64, Release|x64.

Usage

Include ZZ.h in your project:

#include "ZZ.h"

// Construct from integer
ZZ a(42);

// Construct from decimal / hex / binary / octal string
ZZ b("0xFF00");
ZZ c("-12345");

// Arithmetic
ZZ sum  = a + b;
ZZ diff = b - a;
ZZ prod = a * b;

// Division and remainder (preferred)
ZZ quotient, remainder = b;
remainder.QR(a, quotient);   // remainder holds b % a, quotient holds b / a

// Bitwise
ZZ r = a & b;
ZZ s = a | b;
ZZ t = a ^ b;
ZZ u = a << 4;
ZZ v = a >> 4;

// Comparison
bool gt = a > b;
bool eq = a == b;

// Sign / absolute value
intmax_t s = a.sgn();   // -1, 0, or 1
ZZ       av = a.abs();

// Hexadecimal string
std::string hex = a.hexadec(true);   // "0x2A"

API Summary

Constructors

Constructor	Description
ZZ(intmax_t x = 0)	Construct from a native integer
ZZ(const std::string& x)	Construct from a string (decimal, 0x… hex, 0b… binary, 0… octal)
ZZ(const ZZ& x)	Copy constructor

Arithmetic operators

+, -, *, /, %, +=, -=, *=, /=, %=, ++, --, unary -

Note: / and % are functional but not optimised. Prefer QR() when both quotient and remainder are needed.

Bitwise operators

&, |, ^, <<, >>, &=, |=, ^=, <<=, >>=

Comparison operators

==, !=, <, <=, >, >=, ! (zero-check), &&, ||

Other methods

Method	Description
ZZ abs() const	Absolute value
intmax_t sgn() const	Sign: −1, 0, or 1
std::string hexadec(bool prefix) const	Hexadecimal string; prefix=true prepends 0x
ZZ& QR(const ZZ& divisor, ZZ& quotient)	Euclidean division: this becomes remainder, quotient gets the quotient
size_t size() const	Number of internal digit units

Coding notes

See NearNumber/memorandum.txt for style guidelines followed in this project.