mother.cpp

random number generator,随机数产生器

/************************** MOTHER.CPP ****************** AgF 1999-03-03 *
*  'Mother-of-All' random number generator                               *
*                                                                        *
*  This is a multiply-with-carry type of random number generator         *
*  invented by George Marsaglia.  The algorithm is:                      *
*  S = 2111111111*X[n-4] + 1492*X[n-3] + 1776*X[n-2] + 5115*X[n-1] + C   *
*  X[n] = S modulo 2^32                                                  *
*  C = floor(S / 2^32)                                                   *
*                                                                        *
*  IMPORTANT:
*  This implementation uses a long double for C. Note that not all       *
*  computers and compilers support the long double (80-bit) floating     *
*  point format. It is recommended to use a Borland or Gnu compiler on   *
*  a PC. The Microsoft compiler doesn't support the long double format.  *
*  You will get an error message if your system doesn't support this.    *
*                                                                        *
*