cpp/CPrimerPlus6E/Ch12/rand0.c

/* rand0.c –– produces random numbers            */
/*               uses ANSI C portable algorithm  */
static unsigned long int next = 1;  /* the seed  */

unsigned int rand0(void)
{
    /* magic formula to generate pseudorandom number */
    next = next * 1103515245 + 12345;
    return (unsigned int) (next/65536) % 32768;
}