Arbitrary-sized integer class for C++
:construction: Work in progress :construction:
Contents
Highlights
- No additional dependencies apart from the standard library.
- Modern C++ (compiles with C++11 / C++14 / C++17).
- No special compiling or linking required. Simply download the single header file, include it in your code, and compile however you would.
Usage
-
Download the single-include header file to a location under your include path. Then
#include
it in your code:#include "BigInt.hpp" // the actual path may vary
-
Create objects of the
BigInt
class, and do what you got to do!BigInt big1 = 1234567890, big2; big2 = "9876543210123456789098765432101234567890"; std::cout << big1 * big2 * 123456 << "\n"; // Output: 1505331490682966620443288524512589666204282352096057600
Features
Operators
-
Assignment:=
The second operand can either be a
BigInt
, an integer (up tolong long
) or a string (std::string
or a string literal).big1 = 1234567890; big1 = "123456789012345678901234567890"; big1 = big2;
-
Unary arithmetic:+
,-
big1 = +big2; // doesn't return the absolute value big1 = -big2;
-
Binary arithmetic:+
,-
,*
,/
,%
One of the operands has to be a
BigInt
and the other can be aBigInt
, an integer (up tolong long
) or a string (std::string
or a string literal).big1 = big2 + 1234567890; big1 = big2 - "123456789012345678901234567890"; big1 = big2 * big3; big1 = 1234567890 / big2; big1 = "123456789012345678901234567890" % big2;
-
Arithmetic-assignment:+=
,-=
,*=
,/=
,%=
The second operand can either be a
BigInt
, an integer (up tolong long
) or a string (std::string
or a string literal).big1 += big2; big1 -= 1234567890; big1 *= "123456789012345678901234567890"; big1 /= big2; big1 %= 1234567890;
-
Increment and decrement:++
,--
big1 = ++big2; // pre-increment big1 = --big2; // pre-decrement big1 = big2++; // post-increment big1 = big2--; // post-decrement
-
Relational:<
,>
,<=
,>=
,==
,!=
One of the operands has to be a
BigInt
and the other can be aBigInt
, an integer (up tolong long
) or a string (std::string
or a string literal).if (big1 < 1234567890 or big1 > "123456789012345678901234567890" or big1 <= big2 or 1234567890 >= big1 or "123456789012345678901234567890" == big1 or big1 != big3) { ... }
-
I/O stream:<<
,>>
std::cout << big1 << ", " << big2 << "\n"; output_file << big1 << ", " << big2 << "\n"; std::cin >> big1 >> big2; input_file >> big1 >> big2;
Functions
-
Conversion:to_string
,to_int
,to_long
,to_long_long
Convert a
BigInt
to either astring
,int
,long
, orlong long
.Note: If the
BigInt
is beyond the range of the target type, an out_of_range exception is thrown.some_str = big1.to_string(); some_int = big1.to_int(); some_long = big1.to_long(); some_long_long = big1.to_long_long();
-
Math
-
abs
Get the absolute value of a
BigInt
.big1 = abs(big2);
-
big_pow10
Get a
BigInt
equal to 10exp.big1 = big_pow10(5000); // big1 = 10^5000
-
gcd
Get the greatest common divisor (GCD aka. HCF) of two
BigInt
s. One of the arguments can be an integer (up tolong long
) or a string (std::string
or a string literal).big1 = gcd(big2, big3); big1 = gcd(big2, 1234567890); big1 = gcd(big2, "123456789012345678901234567890"); big1 = gcd(1234567890, big2); big1 = gcd("123456789012345678901234567890", big2);
-
lcm
Get the least common multiple (LCM) of two
BigInt
s. One of the arguments can be an integer (up tolong long
) or a string (std::string
or a string literal).big1 = lcm(big2, big3); big1 = lcm(big2, 1234567890); big1 = lcm(big2, "123456789012345678901234567890"); big1 = lcm(1234567890, big2); big1 = lcm("123456789012345678901234567890", big2);
-
pow
Get the value of baseexp as a
BigInt
. The base can either be aBigInt
, an integer (up tolong long
) or a string (std::string
or a string literal).big1 = pow(big2, 789); big1 = pow(987654321LL, 456); // suffix literal with LL to prevent conflicts big1 = pow("1234567890", 123);
-
sqrt
Get the integer square root of a
BigInt
.big1 = sqrt(big2);
-
-
Random
-
big_random
Get a random
BigInt
, that either has a random number of digits (up to 1000), or a specific number of digits.// get a random BigInt that has a random number of digits (up to 1000): big1 = big_random(); // get a random BigInt that has 12345 digits: big1 = big_random(12345);
-
Development
Since this project is built as a header-only library, there are no source files. However, there are unit tests for each header file that the project is split into. These can be compiled and built either through the command line, or using an IDE that has direct support for CMake (such as CLion, Qt Creator) or for which CMake can generate project files (Visual Studio, Eclipse CDT, Code::Blocks and more).
Using the command line
On Linux and macOS, you can compile and run the tests using the command line.
- To compile the tests, run
make
. - To build and run the tests, run
make test
.
Using an IDE that supports CMake
- Load the project directory in your IDE.
- In the build settings for CMake, which can usually be found at
Settings > Build > CMake
, set theGeneration path
tobuild
.
Then you can simply select which target (unit test) you want to build/run, and your IDE will do the rest.
In case your IDE does not support CMake directly, you will need to run cmake
via the command line with the appropriate flags to generate the project files
for your IDE. Give it a try, it's not supposed to be hard!
Contributing
Please read the contributing guidelines for details on how to contribute to the project.
License
This project is licensed under the terms of the MIT license.