#include <stdio.h>
#include <timeb.h>
/*返回随机数序列初值*/
double Initial()
{
    double init;
    struct timeb *tmb;
    while(1)
    {
            ftime(tmb);
            /*利用DOS系统的时钟产生随机数序列初值*/
            init=tmb->millitm*0.9876543*0.001;
            if(init>=0.001)
                break;
    }
    return init;
}
/*返回一个(0,1)之间的随机数*/
double Random(void)
{
    static double rndm=-1.0;
    if(rndm==-1.0)
        rndm=Initial();
    else
        rndm=3.80*rndm*(1.0-rndm);
    return rndm;
}
int main()
{
    double randnum;
    int i;
    clrscr();
    puts("*********************************************");
    puts("| This program can generate a random number |");
    puts("|          Press 'q' to quit                |");
    puts("|     Press any other key to generate       |");
    puts("*********************************************");
    while(1)
    {
          if(getch()=='q')
              break;
            randnum = Random();
            printf ( "\n   >> the randnum is:%f\n",randnum );
    }
    return 0;
}