sample.cc File Reference

#include <string>
#include <iostream>
#include "BigIntegerLibrary.hh"

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Functions
int	main ()

Function Documentation

int main

(

)

Definition at line 10 of file sample.cc.

           {
    /* The library throws `const char *' error messages when things go
     * wrong.  It's a good idea to catch them using a `try' block like this
     * one.  Your C++ compiler might need a command-line option to compile
     * code that uses exceptions. */
    try {
        BigInteger a; // a is 0
        int b = 535;

        /* Any primitive integer can be converted implicitly to a
         * BigInteger. */
        a = b;

        /* The reverse conversion requires a method call (implicit
         * conversions were previously supported but caused trouble).
         * If a were too big for an int, the library would throw an
         * exception. */
        b = a.toInt();

        BigInteger c(a); // Copy a BigInteger.

        // The int literal is converted to a BigInteger.
        BigInteger d(-314159265);

        /* This won't compile (at least on 32-bit machines) because the
         * number is too big to be a primitive integer literal, and
         * there's no such thing as a BigInteger literal. */
        //BigInteger e(3141592653589793238462643383279);

        // Instead you can convert the number from a string.
        std::string s("3141592653589793238462643383279");
        BigInteger f = stringToBigInteger(s);

        // You can convert the other way too.
        std::string s2 = bigIntegerToString(f); 

        // f is implicitly stringified and sent to std::cout.
        std::cout << f << std::endl;

        /* Let's do some math!  The library overloads most of the
         * mathematical operators (including assignment operators) to
         * work on BigIntegers.  There are also ``copy-less''
         * operations; see `BigUnsigned.hh' for details. */

        // Arithmetic operators
        BigInteger g(314159), h(265);
        std::cout << (g + h) << '\n'
            << (g - h) << '\n'
            << (g * h) << '\n'
            << (g / h) << '\n'
            << (g % h) << std::endl;

        // Bitwise operators
        BigUnsigned i(0xFF0000FF), j(0x0000FFFF);
        // The library's << operator recognizes base flags.
        std::cout.flags(std::ios::hex | std::ios::showbase);
        std::cout << (i & j) << '\n'
            << (i | j) << '\n'
            << (i ^ j) << '\n'
            // Shift distances are ordinary unsigned ints.
            << (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
        }

        // Some big-integer algorithms (albeit on small integers).
        std::cout << gcd(BigUnsigned(60), 72) << '\n'
            << modinv(BigUnsigned(7), 11) << '\n'
            << modexp(BigUnsigned(314), 159, 2653) << std::endl;

        // Add your own code here to experiment with the library.
    } catch(char const* err) {
        std::cout << "The library threw an exception:\n"
            << err << std::endl;
    }

    return 0;
}

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