
#include <iostream>
using namespace std;
int Polynomial(double x,int n);
int main ()
{
int n;
double x;
//输入
cout<<"请输入一个实数:";
cin>>x;
cout<<"请输入求n阶勒让德多项式的n值:";
cin>>n;
cout<<"该n阶勒让德多项式的值为:"<<Polynomial(x,n)<<endl;
return 0;
}
int Polynomial(double x,int n)//求n阶勒让德多项式的值的函数
{
double p;
if(n==0)
{
p=1;
}
else if(n==1)
{
p=x;
}
else
{
p=((2*n-1)*x*Polynomial(x,n-1)-(n-1)*Polynomial(x,n-2))/n;
}
return p;
}


