abelmarm / bigint Goto Github PK

🚧 Work in progress 🚧

• Highlights
• Usage
• Features
• Compiling / testing
• Contributing
• License

• 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.

1. 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

2. 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

• Assignment: =

  The second operand can either be a BigInt, an integer (up to long 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 a BigInt, an integer (up to long 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 to long 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 a BigInt, an integer (up to long 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;

• Conversion: to_string, to_int, to_long, to_long_long

  Convert a BigInt to either a string, int, long, or long 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 10^x.

    big1 = big_pow10(5000);   // big1 = 10^5000

Since this project is built as a library, there are no source files. However, there are unit tests for each header file that the project is split into.

• To compile the tests, run make.
• To build and run the tests, run make test.

You will need to run make at least once before you can run make test.

Please read the contributing guidelines for details on how to contribute to the project.

This project is licensed under the terms of the MIT license.