神奇的圆周率

#include <cstdlib>#include <cstdio>#include <iostream>long a = 10000,b,c=2800,d,e,f[2801],g;int res[100],i;int main(){    for(;b-c;)    {        f[b++]=a/5;    }    for(;d=0,g=c*2;c-=14,res[i++]=e+d/a,e=d%a)        for(b=c;d+=f[b]*a,f[b]=d%--g,d/=g--,--b;d*=b);    for(i=0;res[i]!=0;i++)    {        printf("%d",res[i]);    }    return 0;}