圆周率PI的计算(精确到几十万位)

//自然对数的底数e的计算程序
//VC6.0,Console Application
//e=1+1(1+1/2(1+1/3(1+1/4(1+..
#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
long a=100000L;
void main()
{   
     char filename[40];
     unsigned long c,d,e,i,j,ws;
     unsigned long *f,*bb;
     printf("位数? ");
     scanf("%ld",&ws);
     if(ws<1)return;
     c=(ws+4)/05*05;
     bb=f=(long*)malloc(04*c);
     if(f==NULL)abort();
     *bb++=a/5;
     for(i=1;i<c-1;i++)
     *bb++=a/10;
     *bb=a/10;
     for(e=0;c;c-=05,bb-=05,e=d%a)
     {   static long group;
         d=0;i=1;j=c;
         _asm mov eDI,bb
         loopi:
         _asm mov eax,[eDI]
         _asm mul Dword ptr a
         _asm mov ecx,edx
         _asm mov ebx,eax
         _asm mov eax,d
         _asm mul dword ptr i
         _asm add eax,ebx
         _asm adc edx,ecx
         _asm div dword ptr j
         _asm mov d,eax
         _asm mov [eDI],edx
         _asm sub eDI,04
         _asm dec dword ptr j
         _asm jnz loopi
         printf("%05lu\t",e+d/a);
     }
     free(f);
}

//下列程序虽然也能算圆周率π,但是
//仅当位数ws<=16276时,才是正确的
//事实上只要跟踪打了//////////的
//语句就会发现当ws=16000左右就已
//经“溢出”,即把大于2的31次方的
//大整数解读为负数.当ws大于16276
//时情况就变得不能容忍罢了。作为
//补救措施,可以用unsigned long以
//取代long,可正确算至32372位左右
#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
void main()
{   
     long a=10000,c,d,e,i,j,ws,*f;
     printf("位数? ");
     scanf("%ld",&ws);
     if(ws<1)return;
     c=(ws+3)/04*14;
     f=(long*)malloc(04*c);
     if(f==NULL)abort();
     for(i=0;i<c;i++)f[i]=a/5;
     for(e=0;c;c-=14,e=d%a)
     {   d=0;
         for(j=c+c-1,i=c;i;i--,j-=2)
         {
             d=d*i+f[i]*a;//////////
             f[i]=d%j;
             d=d/j;
         }
         printf("%04d",e+d/a);
     }
     printf("\n");
}