Files
ioccc/2000/bellard
Landon Curt Noll a1c86c8a7a add original C links to entry navigation bars
The navigation bar for a winning entry now has a "_Original C_" link
(between the ✅ and the Inventory on the right hand side) so that one
may easily view the original C code that was submitted for IOCCC judging.

Ran `make www timestamp` to perform the above.
2025-08-10 12:46:23 -07:00
..
2022-09-18 23:37:49 -07:00
2023-07-06 21:49:38 -07:00

To build:

    make

To use:

    ./bellard

Judges' remarks:

This code is a nice compact example of a Modular Fast Fourier Transform. While its output is very specific, the internal FFT has a wide variety of uses.

Can you modify this code to produce primes such as 23523*2^70000-1, 48594^65536+1 or 6917!-1?

NOTE: as bigger primes are found as time goes by this program no longer prints the biggest prime once noted by the author below.

Author's comments:

This program prints the biggest known prime number (2^6972593-1) in base 10. It requires a few minutes. It uses a Modular Fast Fourier Transform to compute this number in a reasonable amount of time (the usual method would take ages !).

The program uses >= 64 bit long long type. It should run on any system with a gcc compiler.