Numeric Palindrome Search Program ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (C) 2002, HardCore Software This program is protected by the GNU General Public License. See the file "COPYING" for details. Thanks to defrost for the malloc() tip, and a number of optimizations. Defrost has provided advice upon and contributed optimizations to almost every aspect of this code. What is a Numeric Palindrome ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A numeric palindrome is similar to an alphabetic palindrome: It reads the same both forwards and backwards, for example "A MAN, A PLAN, A CANAL PANAMA", and "12345654321". Most numbers have the property that if added with a number comprised of it's own digits but reversed, they will form a numeric palindrome, or if not immediatley, will become palindromes after iterating this sequence a number of times. Example: 100 + 001 = 101 743 + 347 = 1090 1090 + 0901 = 1991 Certain numbers, most famously 196, don't seem to form palindromes no matter how many time this process is iterated. It is unknown whether eventually they will form palindromes or not, however people have continued this on for many million of iterations - with no end in sight. This program was started after I was inspiried by a slashdot article. I'm not particularly interested in this problem, but it seemed like it would be a fun programming project, so here it is. Why Use This Program ~~~~~~~~~~~~~~~~~~~~ NPSP is quite full featured, and it's features rival, if not surpass any of it's competitors. -Itsvan Standard Formatting for both saving and loading. -Size of computed number is only limited by your memory (and spare time, of course). -Autosaving customizable to the second. -Fairly optimized, thanks to defrost. -Save on exit. -User specified base of 2-16 (defrost's alternate implementation supports 2-36). -Cross platform. -Active memory usage reports. -Active Iterations per second reports. -Free Software (www.fsf.org)! -No bullshit GUI. :) How Do I Use This Program? ~~~~~~~~~~~~~~~~~~~~~~~~~~ NPSP runs on unix and windows. Windows users have been supplied a precompiled binary. You'll find it in windows/npsp.exe. Make sure cygwin1.dll is in the current directory or in your windows directory. Compiling from source: Open up cygwin or fire up a unix console, unpack the archive, switch to the root of the tree, and type: make npsp or make dnpsp npsp is Fractal's original version with some of defrost's optimizations. It also has more features in it's statuc report, along with save on exit. dnpsp is defrost's optimized version, and while not as feature full, is probably somewhat faster. Now you can run ./npsp (from unix or cygwin) npsp (from a DOS prompt) It will show you this: Numeric Palindrome Search Program (NPSP) V1.0 (C) 2002, HardCore SoftWare usage: npsp <options> -i <input file (Istvan Standard Format)> -o <output file (Istvan Standard Format)> -n <seed number> -m <maximum # of digits to find> -b <numeric base> -a <seconds between autosaves> I think it's fairly self-explanitory, so I'll just give you some examples: Compute 196 to 9000 decimal places, and save it in "myfile.ist". ./npsp -n 196 -m 9000 -o myfile.ist Compute a binary lychell number to a million digits, and print the result out. ./npsp -b 2 -n 101001 -m 1000000 Compute an additional thousand digits to your previously saved myfile.ist (see the first example) and save it back into myfile.ist. ./npsp -i myfile.ist -m 10000 -o myfile.ist Notes ~~~~~ Note: When loading files, the -m argument specifies the number of digits to go to, NOT how many more to calculate. Note: Istvan standard format doesn't save base, so be sure to specify the same -b as the one you used to save the file, otherwise you will almost certainly get fucked up results. (This should be fixed in Extended Istvan Format if it ever comes out). Windows users: Make sure cygwin1.dll is in your current directory, or in your windows directory. Windows users: Use this from a DOS prompt. I don't want to say this again. Credits ~~~~~~~ This program is copyright 2002 by: HardCore SoftWare and defrost, The authors can be reached on irc.freenode.net (irc.openprojects.net) on channel #c as Fractal and defrost. This program is protected by the GNU General Public License. See the file "COPYING" for details.