"C + +" recursion after class exercises 3-13, 3-14

////  main.cpp//  3-13递归Fibonacci级数////  Created by T.P on 2018/3/21.//  Copyright ? 2018年 T.P. All rights reserved.////课本习题3-13.用递归的方法编写函数求Fibonacci级数，//公式为：Fn=Fn-1 + Fn-2 （n>2),F1=F2=1#include <iostream>using namespace std;int fibon(int n,int &s){    if (n==2||n==1)        s=1;                        //注意递归归，验证，从最小的地方推    else        s=fibon(n-1,s)+fibon(n-2,s);    return s;}int main(){    int s=0;    int n;    cout<<"请输入Fibonacci级数的n值(n>2)：";    cin>>n;    fibon(n,s);    cout<<s<<endl;    return 0;}

////  main.cpp//  3-14递归n阶勒让德多项式////  Created by T.P on 2018/3/21.//  Copyright ? 2018年 T.P. All rights reserved.////课本习题3-14//Pn(x)=1,  n=0//      =x, n=1//      =[(2n-1)x*Pn-1(x)-(n-1)Pn-2(x)]/n   ,n>1#include <iostream>using namespace std;int LRD(int x,int n){    if(n==0)        return 1;    else if (n==1)        return x;    else        return ((2*n-1)*x*LRD(x, n-1)-(n-1)*LRD(x, n-2))/n;}int main(){    int x,n;    int s=0;    cin>>x>>n;    s=LRD(x, n);    cout<<s<<endl;    return 0;}

"C + +" recursion after class exercises 3-13, 3-14