From: Matt McCutchen Date: Fri, 16 Feb 2007 20:33:27 +0000 (-0500) Subject: - "Modernize" the documentation and sample program. X-Git-Tag: v2007.07.07~4 X-Git-Url: https://mattmccutchen.net/bigint/bigint.git/commitdiff_plain/00c6448a6c5fc7a68427ca1dc3f5f523563e1041 - "Modernize" the documentation and sample program. - Wrap some text to 80-character lines. - Sample program: Fix the number of powers to compute so it can run without user intervention. And increase the base from 3 to 314 to show big numbers without ridiculously long output. --- diff --git a/ChangeLog b/ChangeLog index b31813c..95f607c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,9 +1,10 @@ -+===================================================================+ -Matt McCutchen's Big Integer Library + Change Log -Change Log -========== -These entries tell you what was added, fixed, or improved in each version as compared to the previous one. In case you haven't noticed, a version number roughly corresponds to the release date of that version in `YYYY.MM.DD[.N]' format, where `.N' goes `.2', `.3', etc. if there are multiple versions on the same day. +These entries tell you what was added, fixed, or improved in each version as +compared to the previous one. In case you haven't noticed, a version number +roughly corresponds to the release date of that version in `YYYY.MM.DD[.N]' +format, where `.N' goes `.2', `.3', etc. if there are multiple versions on the +same day. The topmost version listed is the one you have. 2007.02.13 ---------- @@ -77,4 +78,4 @@ Brad Spencer pointed out a memory leak in `BigUnsigned::divide'. It is fixed in --------- After months of inactivity, I fixed a bug in the `BigInteger' division routine; thanks to David Allen for reporting the bug. I also added simple routines for decimal output to `std::ostream's, and there is a demo that prints out powers of 3. -+===================================================================+ +~~~~ diff --git a/README b/README index f45ea24..757637e 100644 --- a/README +++ b/README @@ -1,36 +1,61 @@ -+===================================================================+ -| Big Integer Library | -| A C++ library that does arithmetic on integers of unlimited size. | -| Version 2006.05.01 | -+-------------------------------------------------------------------+ -| By Matt McCutchen | -| E-mail: hashproduct@gmail.com | -| My Web site gateway: http://mysite.verizon.net/hashproduct/ | -| Project Web site: http://www.kepreon.com/~matt/bigint/ | -+===================================================================+ - -What the Big Integer Library provides -===================================== -This library contains two classes, BigUnsigned and BigInteger, that represent nonnegative integers and integers, respectively, of size limited only by your computer's memory. Their capabilities include these operators: - Math: + - * / % & | ^ unary- - Assignment: = += -= *= /= %= &= |= ^= ++ -- - Comparison: == != < <= > >= -In the works are the << and >> operators, integer algorithms like `gcd', and possibly a working implementation of RSA using the library. - -Using the features of the library -================================= -The file `sample.cc' explains and demonstrates the most important features of the library. I recommend that you read `sample.cc' and then run the sample program it contains. If you want to do something not shown in `sample.cc' or want more detail, read the actual header and source files, which are extensively commented. - -Compiling programs with the library -=================================== -The library consists of a folder full of header files (`.hh') and source files (`.cc'). `#include' header files and compile with source files as necessary for your own programs. For those who use `make', a `Makefile' is included that compiles the source code to object files (`.o') and compiles the sample program. - -Bugs -==== -The library has been tested by myself and others but is by no means bug-free. The programs you write using the library will be the best test of its correctness. I urge you to report any problems that you find, whether they come in the form of compiling trouble, mathematically inaccurate results, or runtime memory-management bloopers (which, since I use Java, are altogether too common in my C++). - -Keep in touch -============= -Feel free to e-mail me at `hashproduct@gmail.com' to report bugs or request features. When I fix the bug or add the feature, you will generally be credited by name in the source code and/or the Change Log unless you request otherwise. I am also curious as to what uses you find for the library. New versions of the library will be available at the project Web site. - -===================================================================== \ No newline at end of file + + C++ Big Integer Library + (see ChangeLog for version) + + http://www.kepreon.com/~matt/bigint/ + + Written and maintained by Matt McCutchen + +You can use this library in a C++ program to do arithmetic on integers of size +limited only by your computer's memory. The library provides BigUnsigned and +BigInteger classes that represent nonnegative integers and signed integers, +respectively. Most of the C++ arithmetic operators are overloaded for these +classes, so big-integer calculations are as easy as: + + #include "BigIntegerLibrary.hh" + + BigInteger a = 65536; + cout << (a * a * a * a * a * a * a * a); + + (prints 340282366920938463463374607431768211456) + +The code in `sample.cc' demonstrates the most important features of the library. +To get started quickly, read the code and explanations in that file and run it. +If you want more detail or a feature not shown in `sample.cc', consult the +consult the actual header and source files, which are heavily commented. + +Compiling programs that use the library +--------------------------------------- +The library consists of a folder full of C++ header files (`.hh') and source +files (`.cc'). `#include' header files and compile with source files as +necessary for your own programs. A Makefile is included that compiles the +library source files and the sample program and links them together; you can +easily customize the Makefile to replace the sample with your own program, or +you can write your own Makefile. + +Bugs and enhancements +--------------------- +The library has been tested by me and others but is by no means bug-free. If +you find a bug, please report it to me, whether it comes in the form of +compiling trouble, a mathematically inaccurate result, or a memory-management +blooper (since I use Java, these are altogether too common in my C++). I +generally fix all reported bugs. + +You are also welcome to request enhancements, but I am unlikely to do +substantial amounts of work on enhancements at this point. When I fix a bug you +report or make an enhancement you request, I will generally credit you by name +in the source code and/or the Change Log unless you request otherwise. New +versions of the library will be available at its Web site (above). + +Note +---- +I would be delighted to hear from you if you like this library and/or find a +good use for it. + +Legal +----- +I, Matt McCutchen, the sole author of the original Big Integer Library, waive my +copyright to it, placing it in the public domain. The library comes with +absolutely no warranty. + +~~~~ diff --git a/sample.cc b/sample.cc index 5344781..9a75175 100644 --- a/sample.cc +++ b/sample.cc @@ -1,16 +1,8 @@ /* * Matt McCutchen's Big Integer Library -*/ - -/* -* This sample program demonstrates the most important features of the Big Integer Library. -* To get started quickly, read the code and explanations below. Then try the program out. -* -* If you want more detail or more speed or can't find a feature here, look in the -* appropriate source file. This file shows only the more ``user-friendly'' features; -* the other features are messier but worth learning eventually. * -* GO FORTH and play with many-digit numbers! (c.f. The TeXbook.) +* Sample program demonstrating the most important features of the Big +* Integer Library */ // Standard libraries @@ -25,43 +17,47 @@ int main() { try { - std::cout << "=====\nBig Integer Library Demonstration" << std::endl; - 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. + * 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. - BigInteger d(-314159265); // c is -314159265. The `int' literal is converted to a BigInteger. + // d is -314159265. The `int' literal is converted to a + // BigInteger. + BigInteger d(-314159265); - // Ahem: that's too big to be an `int' literal (or even a `long' literal)! - // Disillusion yourself now -- this won't compile. + // 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); - // Ah. The string is converted to a BigInteger, and strings can be as long as you want. - std::string s2 = easyBItoString(f); // You can convert the other way too. + // You can convert the other way too. + std::string s2 = easyBItoString(f); - std::cout << f << std::endl; // f is stringified and send to std::cout. + // 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 big integers just as with normal integers. The named + * with BigIntegers just as with normal integers. The named * methods `add', `divideWithRemainder', etc. are more advanced * ``put-here operations''; see `BigUnsigned.hh' for details. */ @@ -70,33 +66,22 @@ int main() { std::cout << (g + h) << '\n' << (g - h) << '\n' << (g * h) << '\n' << (g / h) << '\n' << (g % h) << std::endl; - std::cout << "=====\nTest code" << std::endl; + // 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, - * put your own test code here. + * you can add your own test code here. */ - - /* - * (End of test code) - */ - - // Let's do some heavy lifting. - std::cout << "=====\nPowers of 3" << std::endl; - std::cout << "How many do you want?" << std::endl; - int maxPower; - std::cin >> maxPower; - - BigUnsigned x(1), three(3); - for (int power = 0; power <= maxPower; power++) { - std::cout << "3^" << power << " = " << x << std::endl; - x *= three; // A BigInteger assignment operator - } - - std::cout << "There you go. Goodbye.\n=====" << std::endl; + // std::cout << "Beginning of custom test code:\n" << std::endl; } catch(char const* err) { - std::cout << "=====\nSorry, the library threw an exception:\n" + std::cout << "The library threw an exception:\n" << err << std::endl; } @@ -104,7 +89,7 @@ int main() { } /* -* Here is the output of a sample run of this sample program: +Running the sample program produces this output: 3141592653589793238462643383279 314424 @@ -112,12 +97,16 @@ int main() { 83252135 1185 134 -Powers of 3 -How many do you want? -2 -3^0 = 1 -3^1 = 3 -3^2 = 9 -There you go. Goodbye. +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 */