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.