Big Integer class for Cpp

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BigInteger class is used for mathematical operation which involves very big integer calculations that are outside the limit of all available primitive data types.

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🚧 Work in progress 🚧

Contents

• Usage
• Features

Usage

1. Download the bigInt.cpp file to a location under your include path. Then #include it in your code:

   #include "BigInt.cpp"   // 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

Features

Operators

• 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: ++, --

  Increment and Decrement can be done as it is done with general integer types of variables.

  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;

Credit

This Big Int class was created by sujon hasan and farid islam