/* * Sample program demonstrating the most important features of the Big * Integer Library */ // Standard libraries #include #include // For the BigInteger class itself. #include "BigInteger.hh" // For the 4 routines `easy BI/BU <=> string' and `iostream' integration. #include "BigIntegerUtils.hh" int main() { try { BigInteger a; // a is 0 int b = 535; a = b; // From int to BigInteger... b = a; // ...and back, no casts required! /* * If a were too big for an int you'd get a runtime exception. * The Big Integer Library throws C-strings (that is, * `const char *'s) when something goes wrong. It's a good idea * to catch them; the `try/catch' construct wrapping all this * code is an example of how to do this. Some C++ compilers need * a special command-line option to compile code that uses * exceptions. */ BigInteger c(a); // Copy a BigInteger. // d is -314159265. The `int' literal is converted to a // BigInteger. BigInteger d(-314159265); // This won't compile because the number is too big to be an // integer literal. //BigInteger e(3141592653589793238462643383279); // Instead you can convert the number from a string. std::string s("3141592653589793238462643383279"); BigInteger f = easyStringToBI(s); // You can convert the other way too. std::string s2 = easyBItoString(f); // f is stringified and send to std::cout. std::cout << f << std::endl; /* * Let's do some math! * * The Big Integer Library provides lots of overloaded operators * and corresponding assignment operators. So you can do `a + b' * with BigIntegers just as with normal integers. The named * methods `add', `divideWithRemainder', etc. are more advanced * ``put-here operations''; see `BigUnsigned.hh' for details. */ BigInteger g(314159), h(265); // All five ``return-by-value'' arithmetic operators. std::cout << (g + h) << '\n' << (g - h) << '\n' << (g * h) << '\n' << (g / h) << '\n' << (g % h) << std::endl; BigUnsigned i(0xFF0000FF), j(0x0000FFFF); // All five ``return-by-value'' bitwise operators. std::cout.flags(std::ios::hex | std::ios::showbase); std::cout << (i & j) << '\n' << (i | j) << '\n' << (i ^ j) << '\n' << (j << 21) << '\n' << (j >> 10) << '\n'; std::cout.flags(std::ios::dec); // Let's do some heavy lifting and calculate powers of 314. int maxPower = 10; BigUnsigned x(1), big314(314); for (int power = 0; power <= maxPower; power++) { std::cout << "314^" << power << " = " << x << std::endl; x *= big314; // A BigInteger assignment operator } /* * If you want to experiment with the library, * you can add your own test code here. */ // std::cout << "Beginning of custom test code:" << std::endl; } catch(char const* err) { std::cout << "The library threw an exception:\n" << err << std::endl; } return 0; } /* Running the sample program produces this output: 3141592653589793238462643383279 314424 313894 83252135 1185 134 0xFF 0xFF00FFFF 0xFF00FF00 0x1FFFE00000 0x3F 314^0 = 1 314^1 = 314 314^2 = 98596 314^3 = 30959144 314^4 = 9721171216 314^5 = 3052447761824 314^6 = 958468597212736 314^7 = 300959139524799104 314^8 = 94501169810786918656 314^9 = 29673367320587092457984 314^10 = 9317437338664347031806976 */