有些数据可以成功,有些不行
#include <stdio.h>
int main()
{
int n,k;
float pn,x;
float pnc,pnd;
scanf("%f %d\n",&x,&n);
pnd=1;
pnc=x;
if(n==0)
pn=1;
if(n==1)
pn=x;
if(n>1)
for(k=2;k<=n;k++){
pn=(2*k-1)xpnc/k-(k-1)*pnd/k;
pnd=pnc;
pnc=pn;
}
printf("%2.2f",pn);
return 0;
}