大一萌新求问

#include <stdio.h>
int JieCheng(int ShuYi);
int FenZi(int ShuEr);
int main()
{
double a,b=1,d=0;
int c=0;
scanf("%fl",&a);
for(a;a<b;)
{
b=JieCheng(a)/FenZi(a);
c++;
}
for(;c>0;c--){
d=JieCheng(c)/FenZi(c)+d;
}
printf("%.6lf",2*d);
}
int JieCheng(int ShuYi)
{
int ShuChuA=1;
if(ShuYi=1)
{
ShuChuA=1;
}
for(;ShuYi>1;ShuYi--)
{
ShuChuA=ShuChuA*ShuYi;
}
return ShuChuA;
}
int FenZi(int ShuEr)
{
int ShuChuB=1;
for(;ShuEr>0;ShuEr--)
{
ShuChuB=ShuChuB*(2*ShuEr+1);
}
return ShuChuB;
}