#include<stdio.h>#include<math.h>int?deduo(float);int?main(){????float?n,x,sum,result;????scanf("%f?%f",&n,&x);????sum=deduo(n);????printf("%f",sum);????return?0;}int?deduo(float?n){????float?result,x;????if(n==0)????????result=1;????else?if(n==1)????????result=x;????else????????result=((2*n-1)*x*deduo(n-1)-(n-1)*deduo(n-2))/n;????return?result;}其公式為：(凡是n與p相鄰時n是下標）pn(x)={1,(n=0）。x,(n=1)。（（2*n-1）*x*p(n-1)(x)-(n-1)*p(n-2)(x)）/n.